Publish Canary

- @vercel/build-utils@3.0.1-canary.0 - vercel@24.2.2-canary.0
BREAKING CHANGE: updating build-utils to version 3 for DetectorFilesystem changes
2025-12-11 12:57:46 +00:00 · 2022-05-09 13:51:37 -04:00 · 2022-05-09 13:47:11 -04:00 · 2022-05-09 10:24:43 -07:00 · 2022-05-09 17:12:30 +00:00 · 2022-05-09 10:41:56 -04:00
182 changed files with 15896 additions and 1981 deletions
--- a/.vercelignore
+++ b/.vercelignore
@@ -6,6 +6,7 @@
 !.yarnrc
 !yarn.lock
 !package.json
+!turbo.json

 # api
 !api/
@@ -14,4 +15,4 @@
 # packages
 !packages/
 !packages/frameworks
-!packages/frameworks/**
+!packages/frameworks/**
--- a/DEVELOPING_A_RUNTIME.md
+++ b/DEVELOPING_A_RUNTIME.md
@@ -307,15 +307,15 @@ This is a [class](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refere

 This is an abstract enumeration type that is implemented by one of the following possible `String` values:

+- `nodejs14.x`
 - `nodejs12.x`
- `nodejs10.x`
 - `go1.x`
 - `java11`
 - `python3.9`
- `python3.6`
- `dotnetcore2.1`
- `ruby2.5`
- `provided`
+- `dotnet6`
+- `dotnetcore3.1`
+- `ruby2.7`
+- `provided.al2`

 ## `@vercel/build-utils` Helper Functions

--- a/errors/domain-verification.md
+++ b/errors/domain-verification.md
@@ -16,4 +16,4 @@ If you would not like to verify your domain, you can remove it from your account

 #### Resources

- [Vercel Custom Domains Documentation](https://vercel.com/docs/v2/custom-domains)
+- [Vercel Custom Domains Documentation](https://vercel.com/docs/concepts/projects/custom-domains)
--- a/errors/missing-env-file.md
+++ b/errors/missing-env-file.md
@@ -2,7 +2,7 @@

 #### Why This Error Occurred

-You ran `vercel dev` inside a project that contains a `vercel.json` file with `env` or `build.env` properties that use [Vercel Secrets](https://vercel.com/docs/v2/build-step#environment-variables).
+You ran `vercel dev` inside a project that contains a `vercel.json` file with `env` or `build.env` properties that use [Vercel Secrets](https://vercel.com/docs/concepts/projects/environment-variables).

 In order to use environment variables in your project locally that have values defined using the Vercel Secrets format (e.g. `@my-secret-value`), you will need to provide the value as an environment variable using a `.env`.

@@ -24,4 +24,4 @@ TEST=value

 In the above example, `TEST` represents the name of the environment variable and `value` its value.

-For more information on Environment Variables in development, [see the documentation](https://vercel.com/docs/v2/build-step#environment-variables).
+For more information on Environment Variables in development, [see the documentation](https://vercel.com/docs/concepts/projects/environment-variables).
--- a/examples/amp/.gitignore
+++ b/examples/amp/.gitignore
@@ -1 +0,0 @@
-.env
--- a/examples/amp/README.md
+++ b/examples/amp/README.md
@@ -1,19 +0,0 @@
-# AMP Example
-
-This directory is a brief example of an [AMP](https://amp.dev/) site that can be deployed to Vercel with zero configuration.
-
-## Deploy Your Own
-
-Deploy your own AMP project with Vercel.
-
-[![Deploy with Vercel](https://vercel.com/button)](https://vercel.com/new/clone?repository-url=https://github.com/vercel/vercel/tree/main/examples/amp)
-
-_Live Example: https://amp-template.vercel.app_
-
-### How We Created This Example
-
-To get started deploying AMP with Vercel, you can use the [Vercel CLI](https://vercel.com/download) to initialize the project:
-
-```shell
-$ vercel init amp
-```
--- a/examples/amp/favicon.png
+++ b/examples/amp/favicon.png
--- a/examples/amp/index.html
+++ b/examples/amp/index.html
@@ -1,72 +0,0 @@
-<!DOCTYPE html>
-<html ⚡>
-  <head>
-    <meta charset="utf-8" />
-    <meta name="viewport" content="width=device-width,minimum-scale=1" />
-    <link rel="shortcut icon" href="favicon.png">
-    <style amp-boilerplate>body{-webkit-animation:-amp-start 8s steps(1,end) 0s 1 normal both;-moz-animation:-amp-start 8s steps(1,end) 0s 1 normal both;-ms-animation:-amp-start 8s steps(1,end) 0s 1 normal both;animation:-amp-start 8s steps(1,end) 0s 1 normal both}@-webkit-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@-moz-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@-ms-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@-o-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}</style><noscript><style amp-boilerplate>body{-webkit-animation:none;-moz-animation:none;-ms-animation:none;animation:none}</style></noscript>
-    <link rel="canonical" href="index.html" />
-    <title>AMP Website</title>
-    <script async src="https://cdn.ampproject.org/v0.js"></script>
-    <style amp-custom>
-      body > * {
-        margin: 3rem 1rem;
-        font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
-        color: #525252;
-      }
-
-      h3 {
-        font-size: 2rem;
-      }
-
-      h4 {
-        margin-top: 2rem;
-      }
-
-      p {
-        font-size: 1.2rem;
-        line-height: 2rem;
-      }
-
-      .links {
-        display: flex;
-        justify-content: center;
-        margin-bottom: 3rem;
-      }
-
-      .links a {
-        margin: 0 10px;
-        font-size: 1rem;
-        color: #005af0;
-      }
-    </style>
-  </head>
-  <body>
-    <center>
-      <amp-img width=150 height=150 layout="fixed" class="logo" src="logo.png"></amp-img>
-      <h3>Welcome to your AMP page</h3>
-      <p>AMP is a web component framework to <br> easily create user-first websites, stories, ads and emails.</p>
-
-      <h4>Links</h4>
-      <div class="links">
-        <a href="https://amp.dev/">Homepage</a>
-        <a href="https://amp.dev/documentation/guides-and-tutorials/?format=websites">Tutorials</a>
-        <a href="https://amp.dev/documentation/examples/">Examples</a>
-        <a href="https://blog.amp.dev">Blog</a>
-      </div>
-
-      <h4>Ready to get started?</h4>
-      <div class="links">
-        <a href="https://amp.dev/documentation/guides-and-tutorials/start/create/?format=websites">Create your first AMP page</a>
-      </div>
-
-      <h4>Get involved</h4>
-      <div class="links">
-        <a href="https://twitter.com/amphtml">Twitter</a>
-        <a href="https://amphtml.slack.com">Slack</a>
-        <a href="https://amp.dev/events/amp-conf-2019">AMP Conf</a>
-        <a href="https://amp.dev/events/amp-roadshow">AMP Roadshow</a>
-      </div>
-    </center>
-  </body>
-</html>
--- a/examples/amp/logo.png
+++ b/examples/amp/logo.png
--- a/examples/astro/.gitignore
+++ b/examples/astro/.gitignore
@@ -0,0 +1,20 @@
+# build output
+dist/
+.output/
+
+# dependencies
+node_modules/
+
+# logs
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+
+
+# environment variables
+.env
+.env.production
+
+# macOS-specific files
+.DS_Store
--- a/examples/astro/.npmrc
+++ b/examples/astro/.npmrc
@@ -0,0 +1,2 @@
+# Expose Astro dependencies for `pnpm` users
+shamefully-hoist=true
--- a/examples/astro/.vercelignore
+++ b/examples/astro/.vercelignore
@@ -0,0 +1 @@
+README.md
--- a/examples/astro/README.md
+++ b/examples/astro/README.md
@@ -0,0 +1,42 @@
+# Welcome to [Astro](https://astro.build)
+
+[![Open in StackBlitz](https://developer.stackblitz.com/img/open_in_stackblitz.svg)](https://stackblitz.com/github/withastro/astro/tree/latest/examples/starter)
+
+> 🧑‍🚀 **Seasoned astronaut?** Delete this file. Have fun!
+
+## 🚀 Project Structure
+
+Inside of your Astro project, you'll see the following folders and files:
+
+```
+/
+├── public/
+│   └── favicon.ico
+├── src/
+│   ├── components/
+│   │   └── Layout.astro
+│   └── pages/
+│       └── index.astro
+└── package.json
+```
+
+Astro looks for `.astro` or `.md` files in the `src/pages/` directory. Each page is exposed as a route based on its file name.
+
+There's nothing special about `src/components/`, but that's where we like to put any Astro/React/Vue/Svelte/Preact components or layouts.
+
+Any static assets, like images, can be placed in the `public/` directory.
+
+## 🧞 Commands
+
+All commands are run from the root of the project, from a terminal:
+
+| Command           | Action                                       |
+| :---------------- | :------------------------------------------- |
+| `npm install`     | Installs dependencies                        |
+| `npm run dev`     | Starts local dev server at `localhost:3000`  |
+| `npm run build`   | Build your production site to `./dist/`      |
+| `npm run preview` | Preview your build locally, before deploying |
+
+## 👀 Want to learn more?
+
+Feel free to check [our documentation](https://github.com/withastro/astro) or jump into our [Discord server](https://astro.build/chat).
--- a/examples/astro/astro.config.mjs
+++ b/examples/astro/astro.config.mjs
@@ -0,0 +1,4 @@
+import { defineConfig } from 'astro/config';
+
+// https://astro.build/config
+export default defineConfig({});
--- a/examples/astro/package.json
+++ b/examples/astro/package.json
@@ -0,0 +1,14 @@
+{
+  "name": "@example/basics",
+  "version": "0.0.1",
+  "private": true,
+  "scripts": {
+    "dev": "astro dev",
+    "start": "astro dev",
+    "build": "astro build",
+    "preview": "astro preview"
+  },
+  "devDependencies": {
+    "astro": "^1.0.0-beta.20"
+  }
+}
--- a/examples/astro/public/favicon.ico
+++ b/examples/astro/public/favicon.ico
--- a/examples/astro/src/components/Layout.astro
+++ b/examples/astro/src/components/Layout.astro
@@ -0,0 +1,55 @@
+---
+export interface Props {
+	title: string;
+}
+
+const { title } = Astro.props as Props;
+---
+
+<!DOCTYPE html>
+<html lang="en">
+<head>
+	<meta charset="UTF-8">
+	<meta name="viewport" content="width=device-width">
+  <link rel="icon" type="image/x-icon" href="/favicon.ico" />
+	<title>{title}</title>
+</head>
+<body>
+	<slot />
+</body>
+</html>
+
+<style>
+  :root {
+    --font-size-base: clamp(1rem, 0.34vw + 0.91rem, 1.19rem);
+		--font-size-lg: clamp(1.2rem, 0.7vw + 1.2rem, 1.5rem); 
+    --font-size-xl: clamp(2.44rem, 2.38vw + 1.85rem, 3.75rem);
+
+    --color-text: hsl(12, 5%, 4%);
+    --color-bg: hsl(10, 21%, 95%);
+  }
+
+  html {
+    font-family: system-ui, sans-serif;
+    font-size: var(--font-size-base);
+    color: var(--color-text);
+    background-color: var(--color-bg);
+  }
+
+  body {
+    margin: 0;
+  }
+
+  :global(h1) {
+    font-size: var(--font-size-xl);
+  }
+
+  :global(h2) {
+    font-size: var(--font-size-lg);
+  }
+
+  :global(code) {
+    font-family: Menlo, Monaco, Lucida Console, Liberation Mono, DejaVu Sans Mono,
+			Bitstream Vera Sans Mono, Courier New, monospace;
+  }
+</style>
--- a/examples/astro/src/pages/index.astro
+++ b/examples/astro/src/pages/index.astro
@@ -0,0 +1,174 @@
+---
+import Layout from '../components/Layout.astro';
+---
+
+<Layout title="Welcome to Astro.">
+	<main>
+		<h1>Welcome to <span class="text-gradient">Astro</span></h1>
+		<p class="instructions"><strong>Your first mission:</strong> tweak this message to try our hot module reloading. Check the <code>src/pages</code> directory!</p>
+		<ul role="list" class="link-card-grid">
+			<li class="link-card">
+				<a href="https://astro.build/integrations/">
+					<h2>Integrations <span>&rarr;</span></h2>
+					<p>Add component frameworks, Tailwind, Partytown, and more!</p>
+				</a>
+			</li>
+			<li class="link-card">
+				<a href="https://astro.build/themes/">
+					<h2>Themes <span>&rarr;</span></h2>
+					<p>Explore a galaxy of community-built starters.</p>
+				</a>
+			</li>
+			<li class="link-card">
+				<a href="https://docs.astro.build/">
+					<h2>Docs <span>&rarr;</span></h2>
+					<p>Learn our complete feature set and explore the API.</p>
+				</a>
+			</li>
+			<li class="link-card">
+				<a href="https://astro.build/chat/">
+					<h2>Chat <span>&rarr;</span></h2>
+					<p>
+						Ask, contribute, and have fun on our community Discord
+						<svg
+							class="heart"
+							xmlns="http://www.w3.org/2000/svg"
+							viewBox="0 0 512 512"
+							width="16"
+							height="16"
+							fill="currentColor"
+						>
+							<title>heart</title>
+							<path d="M256 448l-30.164-27.211C118.718 322.442 48 258.61 48 179.095 48 114.221 97.918 64 162.4 64c36.399 0 70.717 16.742 93.6 43.947C278.882 80.742 313.199 64 349.6 64 414.082 64 464 114.221 464 179.095c0 79.516-70.719 143.348-177.836 241.694L256 448z" />
+						</svg>
+					</p>
+				</a>
+			</li>
+		</ul>
+	</main>
+</Layout>
+
+<style>
+	:root {
+		--color-border: hsl(17, 24%, 90%);
+		--astro-gradient: linear-gradient(0deg,#4F39FA, #DA62C4);
+		--link-gradient: linear-gradient(45deg, #4F39FA, #DA62C4 30%, var(--color-border) 60%);
+		--night-sky-gradient: linear-gradient(0deg, #392362 -33%, #431f69 10%, #30216b 50%, #1f1638 100%);
+	}
+
+	h2 {
+		margin: 0;
+		transition: color 0.6s cubic-bezier(0.22, 1, 0.36, 1);
+	}
+
+	h2 span {
+		display: inline-block;
+		transition: transform 0.3s cubic-bezier(0.22, 1, 0.36, 1);
+	}
+
+	code {
+		font-size: 0.875em;
+		border: 0.1em solid var(--color-border);
+		border-radius: 4px;
+		padding: 0.15em 0.25em;
+	}
+
+	main {
+		margin: auto;
+    padding: 1em;
+		max-width: 60ch;
+	}
+
+	.text-gradient {
+		font-weight: 900;
+		background-image: var(--astro-gradient);
+		-webkit-background-clip: text;
+  	-webkit-text-fill-color: transparent;
+		background-size: 100% 200%;
+		background-position-y: 100%;
+		border-radius: 0.4rem;
+		animation: pulse 4s ease-in-out infinite;
+	}
+
+	@keyframes pulse {
+		0%, 100% {
+			background-position-y: 0%;
+		}
+		50% {
+			background-position-y: 80%;
+		}
+	}
+
+	.instructions {
+		line-height: 1.8;
+		margin-bottom: 2rem;
+		background-image: var(--night-sky-gradient);
+		padding: 1.5rem;
+		border-radius: 0.4rem;
+		color: var(--color-bg);
+	}
+
+	.link-card-grid {
+		display: grid;
+		grid-template-columns: repeat(auto-fit, minmax(24ch, 1fr));
+		gap: 1rem;
+		padding: 0;
+	}
+
+	.link-card {
+		list-style: none;
+		display: flex;
+		padding: 0.15rem;
+		background-image: var(--link-gradient);
+		background-size: 400%;
+		border-radius: 0.5rem;
+		background-position: 100%;
+		transition: background-position 0.6s cubic-bezier(0.22, 1, 0.36, 1);
+	}
+
+	.link-card > a {
+		width: 100%;
+		text-decoration: none;
+		line-height: 1.4;
+		padding: 1em 1.3em;
+		border-radius: 0.35rem;
+		color: var(--text-color);
+		background-color: white;
+		opacity: 0.8;
+	}
+
+	.link-card:is(:hover, :focus-within) {
+		background-position: 0;
+	}
+
+	.link-card:is(:hover, :focus-within) h2 {
+		color: #4F39FA;
+	}
+
+	.link-card:is(:hover, :focus-within) h2 span {
+		transform: translateX(2px);
+	}
+
+	.heart {
+		display: inline-block;
+		color: #DA62C4;
+		animation: heartbeat 3s ease-in-out infinite;
+	}
+
+	@keyframes heartbeat {
+		0%,
+		50%,
+		100% {
+			transform: scale(1);
+		}
+		5% {
+			transform: scale(1.125);
+		}
+		10% {
+			transform: scale(1.05);
+		}
+		15% {
+			transform: scale(1.25);
+		}
+	}
+</style>
--- a/examples/astro/tsconfig.json
+++ b/examples/astro/tsconfig.json
@@ -0,0 +1,15 @@
+{
+  "compilerOptions": {
+    // Enable top-level await, and other modern ESM features.
+    "target": "ESNext",
+    "module": "ESNext",
+    // Enable node-style module resolution, for things like npm package imports.
+    "moduleResolution": "node",
+    // Enable JSON imports.
+    "resolveJsonModule": true,
+    // Enable stricter transpilation for better output.
+    "isolatedModules": true,
+    // Add type definitions for our Vite runtime.
+    "types": ["vite/client"]
+  }
+}
--- a/examples/astro/yarn.lock
+++ b/examples/astro/yarn.lock
--- a/examples/dojo/README.md
+++ b/examples/dojo/README.md
@@ -6,7 +6,7 @@ This directory is a brief example of a [Dojo](https://dojo.io) site that can be

 Deploy your own Dojo project with Vercel.

-[![Deploy with Vercel](https://vercel.com/button)](https://vercel.com/new/clone?repository-url=https://github.com/vercel/vercel/tree/main/dojo&template=dojo)
+[![Deploy with Vercel](https://vercel.com/button)](https://vercel.com/new/clone?repository-url=https://github.com/vercel/vercel/tree/main/examples/dojo&template=dojo)

 ### How We Created This Example

--- a/examples/ember/.travis.yml
+++ b/examples/ember/.travis.yml
@@ -15,7 +15,7 @@ cache:

 env:
  global:
-    # See https://git.io/vdao3 for details.
+    # See https://github.com/ember-cli/ember-cli/blob/master/docs/build-concurrency.md
    - JOBS=1

 script:
--- a/package.json
+++ b/package.json
@@ -14,37 +14,24 @@
  "dependencies": {
    "lerna": "3.16.4"
  },
-  "turbo": {
-    "baseBranch": "origin/main",
-    "pipeline": {
-      "build": {
-        "dependsOn": [
-          "^build"
-        ],
-        "outputs": [
-          "dist/**"
-        ]
-      }
-    }
-  },
  "devDependencies": {
-    "@typescript-eslint/eslint-plugin": "4.28.0",
-    "@typescript-eslint/parser": "4.28.0",
+    "@typescript-eslint/eslint-plugin": "5.21.0",
+    "@typescript-eslint/parser": "5.21.0",
    "async-retry": "1.2.3",
    "buffer-replace": "1.0.0",
-    "eslint": "7.29.0",
-    "eslint-config-prettier": "8.3.0",
-    "eslint-plugin-jest": "24.3.6",
-    "husky": "6.0.0",
-    "jest": "27.3.1",
+    "eslint": "8.14.0",
+    "eslint-config-prettier": "8.5.0",
+    "eslint-plugin-jest": "26.1.5",
+    "husky": "7.0.4",
+    "jest": "28.0.2",
    "json5": "2.1.1",
    "lint-staged": "9.2.5",
    "node-fetch": "2.6.1",
    "npm-package-arg": "6.1.0",
-    "prettier": "2.3.1",
+    "prettier": "2.6.2",
    "ts-eager": "2.0.2",
-    "ts-jest": "27.0.4",
-    "turbo": "1.1.9"
+    "ts-jest": "28.0.0-next.1",
+    "turbo": "1.2.5"
  },
  "scripts": {
    "lerna": "lerna",
--- a/packages/build-utils/package.json
+++ b/packages/build-utils/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@vercel/build-utils",
-  "version": "2.15.1",
+  "version": "3.0.1-canary.0",
  "license": "MIT",
  "main": "./dist/index.js",
  "types": "./dist/index.d.js",
@@ -23,14 +23,14 @@
    "@types/end-of-stream": "^1.4.0",
    "@types/fs-extra": "9.0.13",
    "@types/glob": "^7.1.1",
-    "@types/jest": "27.0.1",
+    "@types/jest": "27.4.1",
    "@types/js-yaml": "3.12.1",
    "@types/ms": "0.7.31",
    "@types/multistream": "2.1.1",
    "@types/node-fetch": "^2.1.6",
    "@types/semver": "6.0.0",
-    "@types/yazl": "^2.4.1",
-    "@vercel/frameworks": "0.7.1",
+    "@types/yazl": "2.4.2",
+    "@vercel/frameworks": "0.9.0",
    "@vercel/ncc": "0.24.0",
    "aggregate-error": "3.0.1",
    "async-retry": "1.2.3",
@@ -47,6 +47,6 @@
    "node-fetch": "2.6.1",
    "semver": "6.1.1",
    "typescript": "4.3.4",
-    "yazl": "2.4.3"
+    "yazl": "2.5.1"
  }
 }
--- a/packages/build-utils/src/detect-builders.ts
+++ b/packages/build-utils/src/detect-builders.ts
@@ -538,7 +538,7 @@ function getMissingBuildScriptError() {
    code: 'missing_build_script',
    message:
      'Your `package.json` file is missing a `build` property inside the `scripts` property.' +
-      '\nLearn More: https://vercel.com/docs/v2/platform/frequently-asked-questions#missing-build-script',
+      '\nLearn More: https://vercel.link/missing-build-script',
  };
 }

--- a/packages/build-utils/src/detectors/filesystem.ts
+++ b/packages/build-utils/src/detectors/filesystem.ts
@@ -1,3 +1,8 @@
+export interface Stat {
+  name: string;
+  path: string;
+  type: 'file' | 'dir';
+}
 /**
 * `DetectorFilesystem` is an abstract class that represents a virtual filesystem
 * to perform read-only operations on in order to detect which framework is being
@@ -27,15 +32,19 @@ export abstract class DetectorFilesystem {
  protected abstract _hasPath(name: string): Promise<boolean>;
  protected abstract _readFile(name: string): Promise<Buffer>;
  protected abstract _isFile(name: string): Promise<boolean>;
+  protected abstract _readdir(name: string): Promise<Stat[]>;
+  protected abstract _chdir(name: string): DetectorFilesystem;

  private pathCache: Map<string, Promise<boolean>>;
  private fileCache: Map<string, Promise<boolean>>;
  private readFileCache: Map<string, Promise<Buffer>>;
+  private readdirCache: Map<string, Promise<Stat[]>>;

  constructor() {
    this.pathCache = new Map();
    this.fileCache = new Map();
    this.readFileCache = new Map();
+    this.readdirCache = new Map();
  }

  public hasPath = async (path: string): Promise<boolean> => {
@@ -64,4 +73,23 @@ export abstract class DetectorFilesystem {
    }
    return p;
  };
+
+  /**
+   * Returns a list of Stat objects from the current working directory.
+   */
+  public readdir = async (name: string): Promise<Stat[]> => {
+    let p = this.readdirCache.get(name);
+    if (!p) {
+      p = this._readdir(name);
+      this.readdirCache.set(name, p);
+    }
+    return p;
+  };
+
+  /**
+   * Changes the current directory to the specified path and returns a new instance of DetectorFilesystem.
+   */
+  public chdir = (name: string): DetectorFilesystem => {
+    return this._chdir(name);
+  };
 }
--- a/packages/build-utils/src/fs/node-version.ts
+++ b/packages/build-utils/src/fs/node-version.ts
@@ -4,6 +4,7 @@ import { NowBuildError } from '../errors';
 import debug from '../debug';

 const allOptions = [
+  { major: 16, range: '16.x', runtime: 'nodejs16.x' },
  { major: 14, range: '14.x', runtime: 'nodejs14.x' },
  { major: 12, range: '12.x', runtime: 'nodejs12.x' },
  {
--- a/packages/build-utils/src/fs/run-user-scripts.ts
+++ b/packages/build-utils/src/fs/run-user-scripts.ts
@@ -1,15 +1,19 @@
 import assert from 'assert';
 import fs from 'fs-extra';
 import path from 'path';
-import debug from '../debug';
+import Sema from 'async-sema';
 import spawn from 'cross-spawn';
 import { SpawnOptions } from 'child_process';
 import { deprecate } from 'util';
+import debug from '../debug';
 import { NowBuildError } from '../errors';
 import { Meta, PackageJson, NodeVersion, Config } from '../types';
 import { getSupportedNodeVersion, getLatestNodeVersion } from './node-version';
 import { readConfigFile } from './read-config-file';

+// Only allow one `runNpmInstall()` invocation to run concurrently
+const runNpmInstallSema = new Sema(1);
+
 export type CliType = 'yarn' | 'npm' | 'pnpm';

 export interface ScanParentDirsResult {
@@ -17,6 +21,11 @@ export interface ScanParentDirsResult {
   * "yarn", "npm", or "pnpm" depending on the presence of lockfiles.
   */
  cliType: CliType;
+  /**
+   * The file path of found `package.json` file, or `undefined` if none was
+   * found.
+   */
+  packageJsonPath?: string;
  /**
   * The contents of found `package.json` file, when the `readPackageJson`
   * option is enabled.
@@ -237,12 +246,13 @@ export async function scanParentDirs(

  let cliType: CliType = 'yarn';
  let packageJson: PackageJson | undefined;
+  let packageJsonPath: string | undefined;
  let currentDestPath = destPath;
  let lockfileVersion: number | undefined;

  // eslint-disable-next-line no-constant-condition
  while (true) {
-    const packageJsonPath = path.join(currentDestPath, 'package.json');
+    packageJsonPath = path.join(currentDestPath, 'package.json');
    // eslint-disable-next-line no-await-in-loop
    if (await fs.pathExists(packageJsonPath)) {
      // Only read the contents of the *first* `package.json` file found,
@@ -269,15 +279,17 @@ export async function scanParentDirs(
        ),
      ]);

-      if (packageLockJson && !hasYarnLock && !pnpmLockYaml) {
-        cliType = 'npm';
-        lockfileVersion = packageLockJson.lockfileVersion;
-      }
-
-      if (!packageLockJson && !hasYarnLock && pnpmLockYaml) {
+      // Priority order is Yarn > pnpm > npm
+      // - find highest priority lock file and use that
+      if (hasYarnLock) {
+        cliType = 'yarn';
+      } else if (pnpmLockYaml) {
        cliType = 'pnpm';
        // just ensure that it is read as a number and not a string
        lockfileVersion = Number(pnpmLockYaml.lockfileVersion);
+      } else if (packageLockJson) {
+        cliType = 'npm';
+        lockfileVersion = packageLockJson.lockfileVersion;
      }

      // Only stop iterating if a lockfile was found, because it's possible
@@ -293,7 +305,7 @@ export async function scanParentDirs(
    currentDestPath = newDestPath;
  }

-  return { cliType, packageJson, lockfileVersion };
+  return { cliType, packageJson, lockfileVersion, packageJsonPath };
 }

 export async function walkParentDirs({
@@ -319,55 +331,87 @@ export async function walkParentDirs({
  return null;
 }

+function isSet<T>(v: any): v is Set<T> {
+  return v?.constructor?.name === 'Set';
+}
+
 export async function runNpmInstall(
  destPath: string,
  args: string[] = [],
  spawnOpts?: SpawnOptions,
  meta?: Meta,
  nodeVersion?: NodeVersion
-) {
+): Promise<boolean> {
  if (meta?.isDev) {
    debug('Skipping dependency installation because dev mode is enabled');
-    return;
+    return false;
  }

  assert(path.isAbsolute(destPath));
-  debug(`Installing to ${destPath}`);

-  const { cliType, lockfileVersion } = await scanParentDirs(destPath);
-  const opts: SpawnOptionsExtended = { cwd: destPath, ...spawnOpts };
-  const env = opts.env ? { ...opts.env } : { ...process.env };
-  delete env.NODE_ENV;
-  opts.env = getEnvForPackageManager({
-    cliType,
-    lockfileVersion,
-    nodeVersion,
-    env,
-  });
-  let commandArgs: string[];
+  try {
+    await runNpmInstallSema.acquire();
+    const { cliType, packageJsonPath, lockfileVersion } = await scanParentDirs(
+      destPath
+    );

-  if (cliType === 'npm') {
-    opts.prettyCommand = 'npm install';
-    commandArgs = args
-      .filter(a => a !== '--prefer-offline')
-      .concat(['install', '--no-audit', '--unsafe-perm']);
-  } else if (cliType === 'pnpm') {
-    // PNPM's install command is similar to NPM's but without the audit nonsense
-    // @see options https://pnpm.io/cli/install
-    opts.prettyCommand = 'pnpm install';
-    commandArgs = args
-      .filter(a => a !== '--prefer-offline')
-      .concat(['install', '--unsafe-perm']);
-  } else {
-    opts.prettyCommand = 'yarn install';
-    commandArgs = ['install', ...args];
+    // Only allow `runNpmInstall()` to run once per `package.json`
+    // when doing a default install (no additional args)
+    if (meta && packageJsonPath && args.length === 0) {
+      if (!isSet<string>(meta.runNpmInstallSet)) {
+        meta.runNpmInstallSet = new Set<string>();
+      }
+      if (isSet<string>(meta.runNpmInstallSet)) {
+        if (meta.runNpmInstallSet.has(packageJsonPath)) {
+          return false;
+        } else {
+          meta.runNpmInstallSet.add(packageJsonPath);
+        }
+      }
+    }
+
+    const installTime = Date.now();
+    console.log('Installing dependencies...');
+    debug(`Installing to ${destPath}`);
+
+    const opts: SpawnOptionsExtended = { cwd: destPath, ...spawnOpts };
+    const env = opts.env ? { ...opts.env } : { ...process.env };
+    delete env.NODE_ENV;
+    opts.env = getEnvForPackageManager({
+      cliType,
+      lockfileVersion,
+      nodeVersion,
+      env,
+    });
+    let commandArgs: string[];
+
+    if (cliType === 'npm') {
+      opts.prettyCommand = 'npm install';
+      commandArgs = args
+        .filter(a => a !== '--prefer-offline')
+        .concat(['install', '--no-audit', '--unsafe-perm']);
+    } else if (cliType === 'pnpm') {
+      // PNPM's install command is similar to NPM's but without the audit nonsense
+      // @see options https://pnpm.io/cli/install
+      opts.prettyCommand = 'pnpm install';
+      commandArgs = args
+        .filter(a => a !== '--prefer-offline')
+        .concat(['install', '--unsafe-perm']);
+    } else {
+      opts.prettyCommand = 'yarn install';
+      commandArgs = ['install', ...args];
+    }
+
+    if (process.env.NPM_ONLY_PRODUCTION) {
+      commandArgs.push('--production');
+    }
+
+    await spawnAsync(cliType, commandArgs, opts);
+    debug(`Install complete [${Date.now() - installTime}ms]`);
+    return true;
+  } finally {
+    runNpmInstallSema.release();
  }
-
-  if (process.env.NPM_ONLY_PRODUCTION) {
-    commandArgs.push('--production');
-  }
-
-  return spawnAsync(cliType, commandArgs, opts);
 }

 export function getEnvForPackageManager({
@@ -392,6 +436,16 @@ export function getEnvForPackageManager({
      newEnv.PATH = `/node16/bin-npm7:${env.PATH}`;
      console.log('Detected `package-lock.json` generated by npm 7...');
    }
+  } else if (cliType === 'pnpm') {
+    if (
+      typeof lockfileVersion === 'number' &&
+      lockfileVersion === 5.4 &&
+      (nodeVersion?.major || 0) > 12
+    ) {
+      // Ensure that pnpm 7 is at the beginning of the `$PATH`
+      newEnv.PATH = `/pnpm7/pnpm:${env.PATH}`;
+      console.log('Detected `pnpm-lock.yaml` generated by pnpm 7...');
+    }
  } else {
    // Yarn v2 PnP mode may be activated, so force "node-modules" linker style
    if (!env.YARN_NODE_LINKER) {
@@ -502,7 +556,7 @@ export async function runPipInstall(
  meta?: Meta
 ) {
  if (meta && meta.isDev) {
-    debug('Skipping dependency installation because dev mode is enabled');
+    debug('Skipping dependency installation because dev mode is enabled');
    return;
  }

--- a/packages/build-utils/src/index.ts
+++ b/packages/build-utils/src/index.ts
@@ -33,7 +33,6 @@ import {
  getDiscontinuedNodeVersions,
 } from './fs/node-version';
 import streamToBuffer from './fs/stream-to-buffer';
-import shouldServe from './should-serve';
 import debug from './debug';
 import getIgnoreFilter from './get-ignore-filter';
 import { getPlatformEnv } from './get-platform-env';
@@ -73,7 +72,6 @@ export {
  getSpawnOptions,
  getPlatformEnv,
  streamToBuffer,
-  shouldServe,
  debug,
  isSymbolicLink,
  getLambdaOptionsFromFunction,
@@ -94,6 +92,7 @@ export { DetectorFilesystem } from './detectors/filesystem';
 export { readConfigFile } from './fs/read-config-file';
 export { normalizePath } from './fs/normalize-path';

+export * from './should-serve';
 export * from './schemas';
 export * from './types';
 export * from './errors';
@@ -116,3 +115,5 @@ export const isOfficialRuntime = (desired: string, name?: string): boolean => {
 export const isStaticRuntime = (name?: string): boolean => {
  return isOfficialRuntime('static', name);
 };
+
+export { workspaceManagers } from './workspaces/workspace-managers';
--- a/packages/build-utils/src/should-serve.ts
+++ b/packages/build-utils/src/should-serve.ts
@@ -1,12 +1,12 @@
 import { parse } from 'path';
-import { ShouldServeOptions } from './types';
-import FileFsRef from './file-fs-ref';
+import type FileFsRef from './file-fs-ref';
+import type { ShouldServe } from './types';

-export default function shouldServe({
+export const shouldServe: ShouldServe = ({
  entrypoint,
  files,
  requestPath,
-}: ShouldServeOptions): boolean {
+}) => {
  requestPath = requestPath.replace(/\/$/, ''); // sanitize trailing '/'
  entrypoint = entrypoint.replace(/\\/, '/'); // windows compatibility

@@ -20,7 +20,7 @@ export default function shouldServe({
  }

  return false;
-}
+};

 function hasProp(obj: { [path: string]: FileFsRef }, key: string): boolean {
  return Object.hasOwnProperty.call(obj, key);
--- a/packages/build-utils/src/types.ts
+++ b/packages/build-utils/src/types.ts
@@ -332,6 +332,7 @@ export interface ProjectSettings {
  sourceFilesOutsideRootDirectory?: boolean;
  directoryListing?: boolean;
  gitForkProtection?: boolean;
+  commandForIgnoringBuildStep?: string | null;
 }

 export interface BuilderV2 {
@@ -344,6 +345,7 @@ export interface BuilderV3 {
  version: 3;
  build: BuildV3;
  prepareCache?: PrepareCache;
+  shouldServe?: ShouldServe;
  startDevServer?: StartDevServer;
 }

@@ -356,7 +358,29 @@ export interface Images {
  formats?: ImageFormat[];
 }

-export interface BuildResultV2 {
+/**
+ * If a Builder ends up creating filesystem outputs conforming to
+ * the Build Output API, then the Builder should return this type.
+ */
+export interface BuildResultBuildOutput {
+  /**
+   * Version number of the Build Output API that was created.
+   * Currently only `3` is a valid value.
+   * @example 3
+   */
+  buildOutputVersion: 3;
+  /**
+   * Filesystem path to the Build Output directory.
+   * @example "/path/to/.vercel/output"
+   */
+  buildOutputPath: string;
+}
+
+/**
+ * When a Builder implements `version: 2`, the `build()` function is expected
+ * to return this type.
+ */
+export interface BuildResultV2Typical {
  // TODO: use proper `Route` type from `routing-utils` (perhaps move types to a common package)
  routes?: any[];
  images?: Images;
@@ -369,6 +393,8 @@ export interface BuildResultV2 {
  }>;
 }

+export type BuildResultV2 = BuildResultV2Typical | BuildResultBuildOutput;
+
 export interface BuildResultV3 {
  output: Lambda;
 }
@@ -376,6 +402,9 @@ export interface BuildResultV3 {
 export type BuildV2 = (options: BuildOptions) => Promise<BuildResultV2>;
 export type BuildV3 = (options: BuildOptions) => Promise<BuildResultV3>;
 export type PrepareCache = (options: PrepareCacheOptions) => Promise<Files>;
+export type ShouldServe = (
+  options: ShouldServeOptions
+) => boolean | Promise<boolean>;
 export type StartDevServer = (
  options: StartDevServerOptions
 ) => Promise<StartDevServerResult>;
--- a/packages/build-utils/src/workspaces/workspace-managers.ts
+++ b/packages/build-utils/src/workspaces/workspace-managers.ts
@@ -0,0 +1,129 @@
+import type { Framework } from '@vercel/frameworks';
+
+/**
+ * The supported list of workspace managers.
+ *
+ * This list is designed to work with the @see {@link detectFramework} function.
+ *
+ * @example
+ *   import { workspaceManagers as frameworkList } from '@vercel/build-utils/workspaces'
+ *   import { detectFramework } from '@vercel/build-utils'
+ *
+ *   const fs = new GitDetectorFilesystem(...)
+ *   detectFramwork({ fs, frameworkList }) // returns the 'slug' field if detected, otherwise null
+ *
+ * @todo Will be used by the detect-eligible-projects API endpoint for a given git url.
+ */
+export const workspaceManagers: Array<Framework> = [
+  {
+    name: 'Yarn',
+    slug: 'yarn',
+    detectors: {
+      every: [
+        {
+          path: 'package.json',
+          matchContent:
+            '"workspaces":\\s*(?:\\[[^\\]]*]|{[^}]*"packages":[^}]*})',
+        },
+        {
+          path: 'yarn.lock',
+        },
+      ],
+    },
+    // unused props - needed for typescript
+    description: '',
+    logo: '',
+    settings: {
+      buildCommand: {
+        value: '',
+        placeholder: '',
+      },
+      devCommand: {
+        value: '',
+        placeholder: '',
+      },
+      installCommand: {
+        value: '',
+        placeholder: '',
+      },
+      outputDirectory: {
+        value: '',
+        placeholder: '',
+      },
+    },
+    getOutputDirName: () => Promise.resolve(''),
+  },
+  {
+    name: 'pnpm',
+    slug: 'pnpm',
+    detectors: {
+      every: [
+        {
+          path: 'pnpm-workspace.yaml',
+        },
+      ],
+    },
+    // unused props - needed for typescript
+    description: '',
+    logo: '',
+    settings: {
+      buildCommand: {
+        value: '',
+        placeholder: '',
+      },
+      devCommand: {
+        value: '',
+        placeholder: '',
+      },
+      installCommand: {
+        value: '',
+        placeholder: '',
+      },
+      outputDirectory: {
+        value: '',
+        placeholder: '',
+      },
+    },
+    getOutputDirName: () => Promise.resolve(''),
+  },
+  {
+    name: 'npm',
+    slug: 'npm',
+    detectors: {
+      every: [
+        {
+          path: 'package.json',
+          matchContent:
+            '"workspaces":\\s*(?:\\[[^\\]]*]|{[^}]*"packages":[^}]*})',
+        },
+        {
+          path: 'package-lock.json',
+        },
+      ],
+    },
+    // unused props - needed for typescript
+    description: '',
+    logo: '',
+    settings: {
+      buildCommand: {
+        value: '',
+        placeholder: '',
+      },
+      devCommand: {
+        value: '',
+        placeholder: '',
+      },
+      installCommand: {
+        value: '',
+        placeholder: '',
+      },
+      outputDirectory: {
+        value: '',
+        placeholder: '',
+      },
+    },
+    getOutputDirName: () => Promise.resolve(''),
+  },
+];
+
+export default workspaceManagers;
--- a/packages/build-utils/test/fixtures/02-zero-config-api/yarn.lock
+++ b/packages/build-utils/test/fixtures/02-zero-config-api/yarn.lock
@@ -0,0 +1,4 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
--- a/packages/build-utils/test/fixtures/25-multiple-lock-files-yarn/package-lock.json
+++ b/packages/build-utils/test/fixtures/25-multiple-lock-files-yarn/package-lock.json
--- a/packages/build-utils/test/fixtures/25-multiple-lock-files-yarn/package.json
+++ b/packages/build-utils/test/fixtures/25-multiple-lock-files-yarn/package.json
@@ -0,0 +1,14 @@
+{
+  "private": "true",
+  "name": "25-multiple-lock-files-yarn",
+  "workspaces": [
+    "a",
+    "b"
+  ],
+  "scripts": {
+    "build": "mkdir -p public && (printf \"yarn version: \" && yarn -v) > public/index.txt"
+  },
+  "dependencies": {
+    "once": "^1.4.0"
+  }
+}
--- a/packages/build-utils/test/fixtures/25-multiple-lock-files-yarn/pnpm-lock.yaml
+++ b/packages/build-utils/test/fixtures/25-multiple-lock-files-yarn/pnpm-lock.yaml
@@ -0,0 +1,19 @@
+lockfileVersion: 5.3
+
+specifiers:
+  once: ^1.4.0
+
+dependencies:
+  once: 1.4.0
+
+packages:
+
+  /once/1.4.0:
+    resolution: {integrity: sha1-WDsap3WWHUsROsF9nFC6753Xa9E=}
+    dependencies:
+      wrappy: 1.0.2
+    dev: false
+
+  /wrappy/1.0.2:
+    resolution: {integrity: sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8=}
+    dev: false
--- a/packages/build-utils/test/fixtures/25-multiple-lock-files-yarn/vercel.json
+++ b/packages/build-utils/test/fixtures/25-multiple-lock-files-yarn/vercel.json
@@ -0,0 +1,11 @@
+{
+  "version": 2,
+  "builds": [{ "src": "package.json", "use": "@vercel/static-build" }],
+  "probes": [
+    {
+      "path": "/",
+      "mustContain": "yarn version: 1",
+      "logMustContain": "yarn run build"
+    }
+  ]
+}
--- a/packages/build-utils/test/fixtures/25-multiple-lock-files-yarn/yarn.lock
+++ b/packages/build-utils/test/fixtures/25-multiple-lock-files-yarn/yarn.lock
@@ -0,0 +1,15 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+once@^1.4.0:
+  version "1.4.0"
+  resolved "https://registry.yarnpkg.com/once/-/once-1.4.0.tgz#583b1aa775961d4b113ac17d9c50baef9dd76bd1"
+  integrity sha1-WDsap3WWHUsROsF9nFC6753Xa9E=
+  dependencies:
+    wrappy "1"
+
+wrappy@1:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/wrappy/-/wrappy-1.0.2.tgz#b5243d8f3ec1aa35f1364605bc0d1036e30ab69f"
+  integrity sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8=
--- a/packages/build-utils/test/fixtures/26-multiple-lock-files-pnpm/package-lock.json
+++ b/packages/build-utils/test/fixtures/26-multiple-lock-files-pnpm/package-lock.json
@@ -0,0 +1,44 @@
+{
+  "name": "26-multiple-lock-files-pnpm",
+  "version": "1.0.0",
+  "lockfileVersion": 2,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "26-multiple-lock-files-pnpm",
+      "version": "1.0.0",
+      "license": "ISC",
+      "dependencies": {
+        "once": "^1.4.0"
+      }
+    },
+    "node_modules/once": {
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/once/-/once-1.4.0.tgz",
+      "integrity": "sha1-WDsap3WWHUsROsF9nFC6753Xa9E=",
+      "dependencies": {
+        "wrappy": "1"
+      }
+    },
+    "node_modules/wrappy": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.2.tgz",
+      "integrity": "sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8="
+    }
+  },
+  "dependencies": {
+    "once": {
+      "version": "1.4.0",
+      "resolved": "https://registry.npmjs.org/once/-/once-1.4.0.tgz",
+      "integrity": "sha1-WDsap3WWHUsROsF9nFC6753Xa9E=",
+      "requires": {
+        "wrappy": "1"
+      }
+    },
+    "wrappy": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.2.tgz",
+      "integrity": "sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8="
+    }
+  }
+}
--- a/packages/build-utils/test/fixtures/26-multiple-lock-files-pnpm/package.json
+++ b/packages/build-utils/test/fixtures/26-multiple-lock-files-pnpm/package.json
@@ -0,0 +1,14 @@
+{
+  "private": "true",
+  "name": "26-multiple-lock-files-pnpm",
+  "workspaces": [
+    "a",
+    "b"
+  ],
+  "scripts": {
+    "build": "mkdir -p public && (printf \"pnpm version: \" && pnpm -v) > public/index.txt"
+  },
+  "dependencies": {
+    "once": "^1.4.0"
+  }
+}
--- a/packages/build-utils/test/fixtures/26-multiple-lock-files-pnpm/pnpm-lock.yaml
+++ b/packages/build-utils/test/fixtures/26-multiple-lock-files-pnpm/pnpm-lock.yaml
@@ -0,0 +1,19 @@
+lockfileVersion: 5.3
+
+specifiers:
+  once: ^1.4.0
+
+dependencies:
+  once: 1.4.0
+
+packages:
+
+  /once/1.4.0:
+    resolution: {integrity: sha1-WDsap3WWHUsROsF9nFC6753Xa9E=}
+    dependencies:
+      wrappy: 1.0.2
+    dev: false
+
+  /wrappy/1.0.2:
+    resolution: {integrity: sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8=}
+    dev: false
--- a/packages/build-utils/test/fixtures/26-multiple-lock-files-pnpm/pnpm-workspace.yaml
+++ b/packages/build-utils/test/fixtures/26-multiple-lock-files-pnpm/pnpm-workspace.yaml
@@ -0,0 +1,3 @@
+packages:
+  - 'a'
+  - 'b'
--- a/packages/build-utils/test/fixtures/26-multiple-lock-files-pnpm/vercel.json
+++ b/packages/build-utils/test/fixtures/26-multiple-lock-files-pnpm/vercel.json
@@ -0,0 +1,11 @@
+{
+  "version": 2,
+  "builds": [{ "src": "package.json", "use": "@vercel/static-build" }],
+  "probes": [
+    {
+      "path": "/",
+      "mustContain": "pnpm version: 6",
+      "logMustContain": "pnpm run build"
+    }
+  ]
+}
--- a/packages/build-utils/test/fixtures/27-yarn-workspaces/a/package.json
+++ b/packages/build-utils/test/fixtures/27-yarn-workspaces/a/package.json
@@ -0,0 +1,15 @@
+{
+  "name": "a",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "debug": "^4.3.2"
+  }
+}
--- a/packages/build-utils/test/fixtures/27-yarn-workspaces/b/package.json
+++ b/packages/build-utils/test/fixtures/27-yarn-workspaces/b/package.json
@@ -0,0 +1,15 @@
+{
+  "name": "b",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "cowsay": "^1.5.0"
+  }
+}
--- a/packages/build-utils/test/fixtures/27-yarn-workspaces/package.json
+++ b/packages/build-utils/test/fixtures/27-yarn-workspaces/package.json
@@ -0,0 +1,9 @@
+{
+  "name": "21-npm-workspaces",
+  "version": "1.0.0",
+  "private": true,
+  "workspaces": [
+    "a",
+    "b"
+  ]
+}
--- a/packages/build-utils/test/fixtures/27-yarn-workspaces/yarn.lock
+++ b/packages/build-utils/test/fixtures/27-yarn-workspaces/yarn.lock
@@ -0,0 +1,232 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+ansi-regex@^3.0.0:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/ansi-regex/-/ansi-regex-3.0.1.tgz#123d6479e92ad45ad897d4054e3c7ca7db4944e1"
+  integrity sha512-+O9Jct8wf++lXxxFc4hc8LsjaSq0HFzzL7cVsw8pRDIPdjKD2mT4ytDZlLuSBZ4cLKZFXIrMGO7DbQCtMJJMKw==
+
+ansi-regex@^5.0.1:
+  version "5.0.1"
+  resolved "https://registry.yarnpkg.com/ansi-regex/-/ansi-regex-5.0.1.tgz#082cb2c89c9fe8659a311a53bd6a4dc5301db304"
+  integrity sha512-quJQXlTSUGL2LH9SUXo8VwsY4soanhgo6LNSm84E1LBcE8s3O0wpdiRzyR9z/ZZJMlMWv37qOOb9pdJlMUEKFQ==
+
+ansi-styles@^4.0.0:
+  version "4.3.0"
+  resolved "https://registry.yarnpkg.com/ansi-styles/-/ansi-styles-4.3.0.tgz#edd803628ae71c04c85ae7a0906edad34b648937"
+  integrity sha512-zbB9rCJAT1rbjiVDb2hqKFHNYLxgtk8NURxZ3IZwD3F6NtxbXZQCnnSi1Lkx+IDohdPlFp222wVALIheZJQSEg==
+  dependencies:
+    color-convert "^2.0.1"
+
+camelcase@^5.0.0:
+  version "5.3.1"
+  resolved "https://registry.yarnpkg.com/camelcase/-/camelcase-5.3.1.tgz#e3c9b31569e106811df242f715725a1f4c494320"
+  integrity sha512-L28STB170nwWS63UjtlEOE3dldQApaJXZkOI1uMFfzf3rRuPegHaHesyee+YxQ+W6SvRDQV6UrdOdRiR153wJg==
+
+cliui@^6.0.0:
+  version "6.0.0"
+  resolved "https://registry.yarnpkg.com/cliui/-/cliui-6.0.0.tgz#511d702c0c4e41ca156d7d0e96021f23e13225b1"
+  integrity sha512-t6wbgtoCXvAzst7QgXxJYqPt0usEfbgQdftEPbLL/cvv6HPE5VgvqCuAIDR0NgU52ds6rFwqrgakNLrHEjCbrQ==
+  dependencies:
+    string-width "^4.2.0"
+    strip-ansi "^6.0.0"
+    wrap-ansi "^6.2.0"
+
+color-convert@^2.0.1:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/color-convert/-/color-convert-2.0.1.tgz#72d3a68d598c9bdb3af2ad1e84f21d896abd4de3"
+  integrity sha512-RRECPsj7iu/xb5oKYcsFHSppFNnsj/52OVTRKb4zP5onXwVF3zVmmToNcOfGC+CRDpfK/U584fMg38ZHCaElKQ==
+  dependencies:
+    color-name "~1.1.4"
+
+color-name@~1.1.4:
+  version "1.1.4"
+  resolved "https://registry.yarnpkg.com/color-name/-/color-name-1.1.4.tgz#c2a09a87acbde69543de6f63fa3995c826c536a2"
+  integrity sha512-dOy+3AuW3a2wNbZHIuMZpTcgjGuLU/uBL/ubcZF9OXbDo8ff4O8yVp5Bf0efS8uEoYo5q4Fx7dY9OgQGXgAsQA==
+
+cowsay@^1.5.0:
+  version "1.5.0"
+  resolved "https://registry.yarnpkg.com/cowsay/-/cowsay-1.5.0.tgz#4a2a453b8b59383c7d7a50e44d765c5de0bf615f"
+  integrity sha512-8Ipzr54Z8zROr/62C8f0PdhQcDusS05gKTS87xxdji8VbWefWly0k8BwGK7+VqamOrkv3eGsCkPtvlHzrhWsCA==
+  dependencies:
+    get-stdin "8.0.0"
+    string-width "~2.1.1"
+    strip-final-newline "2.0.0"
+    yargs "15.4.1"
+
+debug@^4.3.2:
+  version "4.3.4"
+  resolved "https://registry.yarnpkg.com/debug/-/debug-4.3.4.tgz#1319f6579357f2338d3337d2cdd4914bb5dcc865"
+  integrity sha512-PRWFHuSU3eDtQJPvnNY7Jcket1j0t5OuOsFzPPzsekD52Zl8qUfFIPEiswXqIvHWGVHOgX+7G/vCNNhehwxfkQ==
+  dependencies:
+    ms "2.1.2"
+
+decamelize@^1.2.0:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/decamelize/-/decamelize-1.2.0.tgz#f6534d15148269b20352e7bee26f501f9a191290"
+  integrity sha1-9lNNFRSCabIDUue+4m9QH5oZEpA=
+
+emoji-regex@^8.0.0:
+  version "8.0.0"
+  resolved "https://registry.yarnpkg.com/emoji-regex/-/emoji-regex-8.0.0.tgz#e818fd69ce5ccfcb404594f842963bf53164cc37"
+  integrity sha512-MSjYzcWNOA0ewAHpz0MxpYFvwg6yjy1NG3xteoqz644VCo/RPgnr1/GGt+ic3iJTzQ8Eu3TdM14SawnVUmGE6A==
+
+find-up@^4.1.0:
+  version "4.1.0"
+  resolved "https://registry.yarnpkg.com/find-up/-/find-up-4.1.0.tgz#97afe7d6cdc0bc5928584b7c8d7b16e8a9aa5d19"
+  integrity sha512-PpOwAdQ/YlXQ2vj8a3h8IipDuYRi3wceVQQGYWxNINccq40Anw7BlsEXCMbt1Zt+OLA6Fq9suIpIWD0OsnISlw==
+  dependencies:
+    locate-path "^5.0.0"
+    path-exists "^4.0.0"
+
+get-caller-file@^2.0.1:
+  version "2.0.5"
+  resolved "https://registry.yarnpkg.com/get-caller-file/-/get-caller-file-2.0.5.tgz#4f94412a82db32f36e3b0b9741f8a97feb031f7e"
+  integrity sha512-DyFP3BM/3YHTQOCUL/w0OZHR0lpKeGrxotcHWcqNEdnltqFwXVfhEBQ94eIo34AfQpo0rGki4cyIiftY06h2Fg==
+
+get-stdin@8.0.0:
+  version "8.0.0"
+  resolved "https://registry.yarnpkg.com/get-stdin/-/get-stdin-8.0.0.tgz#cbad6a73feb75f6eeb22ba9e01f89aa28aa97a53"
+  integrity sha512-sY22aA6xchAzprjyqmSEQv4UbAAzRN0L2dQB0NlN5acTTK9Don6nhoc3eAbUnpZiCANAMfd/+40kVdKfFygohg==
+
+is-fullwidth-code-point@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/is-fullwidth-code-point/-/is-fullwidth-code-point-2.0.0.tgz#a3b30a5c4f199183167aaab93beefae3ddfb654f"
+  integrity sha1-o7MKXE8ZkYMWeqq5O+764937ZU8=
+
+is-fullwidth-code-point@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/is-fullwidth-code-point/-/is-fullwidth-code-point-3.0.0.tgz#f116f8064fe90b3f7844a38997c0b75051269f1d"
+  integrity sha512-zymm5+u+sCsSWyD9qNaejV3DFvhCKclKdizYaJUuHA83RLjb7nSuGnddCHGv0hk+KY7BMAlsWeK4Ueg6EV6XQg==
+
+locate-path@^5.0.0:
+  version "5.0.0"
+  resolved "https://registry.yarnpkg.com/locate-path/-/locate-path-5.0.0.tgz#1afba396afd676a6d42504d0a67a3a7eb9f62aa0"
+  integrity sha512-t7hw9pI+WvuwNJXwk5zVHpyhIqzg2qTlklJOf0mVxGSbe3Fp2VieZcduNYjaLDoy6p9uGpQEGWG87WpMKlNq8g==
+  dependencies:
+    p-locate "^4.1.0"
+
+ms@2.1.2:
+  version "2.1.2"
+  resolved "https://registry.yarnpkg.com/ms/-/ms-2.1.2.tgz#d09d1f357b443f493382a8eb3ccd183872ae6009"
+  integrity sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w==
+
+p-limit@^2.2.0:
+  version "2.3.0"
+  resolved "https://registry.yarnpkg.com/p-limit/-/p-limit-2.3.0.tgz#3dd33c647a214fdfffd835933eb086da0dc21db1"
+  integrity sha512-//88mFWSJx8lxCzwdAABTJL2MyWB12+eIY7MDL2SqLmAkeKU9qxRvWuSyTjm3FUmpBEMuFfckAIqEaVGUDxb6w==
+  dependencies:
+    p-try "^2.0.0"
+
+p-locate@^4.1.0:
+  version "4.1.0"
+  resolved "https://registry.yarnpkg.com/p-locate/-/p-locate-4.1.0.tgz#a3428bb7088b3a60292f66919278b7c297ad4f07"
+  integrity sha512-R79ZZ/0wAxKGu3oYMlz8jy/kbhsNrS7SKZ7PxEHBgJ5+F2mtFW2fK2cOtBh1cHYkQsbzFV7I+EoRKe6Yt0oK7A==
+  dependencies:
+    p-limit "^2.2.0"
+
+p-try@^2.0.0:
+  version "2.2.0"
+  resolved "https://registry.yarnpkg.com/p-try/-/p-try-2.2.0.tgz#cb2868540e313d61de58fafbe35ce9004d5540e6"
+  integrity sha512-R4nPAVTAU0B9D35/Gk3uJf/7XYbQcyohSKdvAxIRSNghFl4e71hVoGnBNQz9cWaXxO2I10KTC+3jMdvvoKw6dQ==
+
+path-exists@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/path-exists/-/path-exists-4.0.0.tgz#513bdbe2d3b95d7762e8c1137efa195c6c61b5b3"
+  integrity sha512-ak9Qy5Q7jYb2Wwcey5Fpvg2KoAc/ZIhLSLOSBmRmygPsGwkVVt0fZa0qrtMz+m6tJTAHfZQ8FnmB4MG4LWy7/w==
+
+require-directory@^2.1.1:
+  version "2.1.1"
+  resolved "https://registry.yarnpkg.com/require-directory/-/require-directory-2.1.1.tgz#8c64ad5fd30dab1c976e2344ffe7f792a6a6df42"
+  integrity sha1-jGStX9MNqxyXbiNE/+f3kqam30I=
+
+require-main-filename@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/require-main-filename/-/require-main-filename-2.0.0.tgz#d0b329ecc7cc0f61649f62215be69af54aa8989b"
+  integrity sha512-NKN5kMDylKuldxYLSUfrbo5Tuzh4hd+2E8NPPX02mZtn1VuREQToYe/ZdlJy+J3uCpfaiGF05e7B8W0iXbQHmg==
+
+set-blocking@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/set-blocking/-/set-blocking-2.0.0.tgz#045f9782d011ae9a6803ddd382b24392b3d890f7"
+  integrity sha1-BF+XgtARrppoA93TgrJDkrPYkPc=
+
+string-width@^4.1.0, string-width@^4.2.0:
+  version "4.2.3"
+  resolved "https://registry.yarnpkg.com/string-width/-/string-width-4.2.3.tgz#269c7117d27b05ad2e536830a8ec895ef9c6d010"
+  integrity sha512-wKyQRQpjJ0sIp62ErSZdGsjMJWsap5oRNihHhu6G7JVO/9jIB6UyevL+tXuOqrng8j/cxKTWyWUwvSTriiZz/g==
+  dependencies:
+    emoji-regex "^8.0.0"
+    is-fullwidth-code-point "^3.0.0"
+    strip-ansi "^6.0.1"
+
+string-width@~2.1.1:
+  version "2.1.1"
+  resolved "https://registry.yarnpkg.com/string-width/-/string-width-2.1.1.tgz#ab93f27a8dc13d28cac815c462143a6d9012ae9e"
+  integrity sha512-nOqH59deCq9SRHlxq1Aw85Jnt4w6KvLKqWVik6oA9ZklXLNIOlqg4F2yrT1MVaTjAqvVwdfeZ7w7aCvJD7ugkw==
+  dependencies:
+    is-fullwidth-code-point "^2.0.0"
+    strip-ansi "^4.0.0"
+
+strip-ansi@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/strip-ansi/-/strip-ansi-4.0.0.tgz#a8479022eb1ac368a871389b635262c505ee368f"
+  integrity sha1-qEeQIusaw2iocTibY1JixQXuNo8=
+  dependencies:
+    ansi-regex "^3.0.0"
+
+strip-ansi@^6.0.0, strip-ansi@^6.0.1:
+  version "6.0.1"
+  resolved "https://registry.yarnpkg.com/strip-ansi/-/strip-ansi-6.0.1.tgz#9e26c63d30f53443e9489495b2105d37b67a85d9"
+  integrity sha512-Y38VPSHcqkFrCpFnQ9vuSXmquuv5oXOKpGeT6aGrr3o3Gc9AlVa6JBfUSOCnbxGGZF+/0ooI7KrPuUSztUdU5A==
+  dependencies:
+    ansi-regex "^5.0.1"
+
+strip-final-newline@2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/strip-final-newline/-/strip-final-newline-2.0.0.tgz#89b852fb2fcbe936f6f4b3187afb0a12c1ab58ad"
+  integrity sha512-BrpvfNAE3dcvq7ll3xVumzjKjZQ5tI1sEUIKr3Uoks0XUl45St3FlatVqef9prk4jRDzhW6WZg+3bk93y6pLjA==
+
+which-module@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/which-module/-/which-module-2.0.0.tgz#d9ef07dce77b9902b8a3a8fa4b31c3e3f7e6e87a"
+  integrity sha1-2e8H3Od7mQK4o6j6SzHD4/fm6Ho=
+
+wrap-ansi@^6.2.0:
+  version "6.2.0"
+  resolved "https://registry.yarnpkg.com/wrap-ansi/-/wrap-ansi-6.2.0.tgz#e9393ba07102e6c91a3b221478f0257cd2856e53"
+  integrity sha512-r6lPcBGxZXlIcymEu7InxDMhdW0KDxpLgoFLcguasxCaJ/SOIZwINatK9KY/tf+ZrlywOKU0UDj3ATXUBfxJXA==
+  dependencies:
+    ansi-styles "^4.0.0"
+    string-width "^4.1.0"
+    strip-ansi "^6.0.0"
+
+y18n@^4.0.0:
+  version "4.0.3"
+  resolved "https://registry.yarnpkg.com/y18n/-/y18n-4.0.3.tgz#b5f259c82cd6e336921efd7bfd8bf560de9eeedf"
+  integrity sha512-JKhqTOwSrqNA1NY5lSztJ1GrBiUodLMmIZuLiDaMRJ+itFd+ABVE8XBjOvIWL+rSqNDC74LCSFmlb/U4UZ4hJQ==
+
+yargs-parser@^18.1.2:
+  version "18.1.3"
+  resolved "https://registry.yarnpkg.com/yargs-parser/-/yargs-parser-18.1.3.tgz#be68c4975c6b2abf469236b0c870362fab09a7b0"
+  integrity sha512-o50j0JeToy/4K6OZcaQmW6lyXXKhq7csREXcDwk2omFPJEwUNOVtJKvmDr9EI1fAJZUyZcRF7kxGBWmRXudrCQ==
+  dependencies:
+    camelcase "^5.0.0"
+    decamelize "^1.2.0"
+
+yargs@15.4.1:
+  version "15.4.1"
+  resolved "https://registry.yarnpkg.com/yargs/-/yargs-15.4.1.tgz#0d87a16de01aee9d8bec2bfbf74f67851730f4f8"
+  integrity sha512-aePbxDmcYW++PaqBsJ+HYUFwCdv4LVvdnhBy78E57PIor8/OVvhMrADFFEDh8DHDFRv/O9i3lPhsENjO7QX0+A==
+  dependencies:
+    cliui "^6.0.0"
+    decamelize "^1.2.0"
+    find-up "^4.1.0"
+    get-caller-file "^2.0.1"
+    require-directory "^2.1.1"
+    require-main-filename "^2.0.0"
+    set-blocking "^2.0.0"
+    string-width "^4.2.0"
+    which-module "^2.0.0"
+    y18n "^4.0.0"
+    yargs-parser "^18.1.2"
--- a/packages/build-utils/test/fixtures/28-pnpm-7/package.json
+++ b/packages/build-utils/test/fixtures/28-pnpm-7/package.json
@@ -0,0 +1,9 @@
+{
+  "private": "true",
+  "scripts": {
+    "build": "mkdir -p public && (printf \"pnpm version: \" && pnpm -v) > public/index.txt"
+  },
+  "dependencies": {
+    "once": "^1.4.0"
+  }
+}
--- a/packages/build-utils/test/fixtures/28-pnpm-7/pnpm-lock.yaml
+++ b/packages/build-utils/test/fixtures/28-pnpm-7/pnpm-lock.yaml
@@ -0,0 +1,19 @@
+lockfileVersion: 5.4
+
+specifiers:
+  once: ^1.4.0
+
+dependencies:
+  once: 1.4.0
+
+packages:
+
+  /once/1.4.0:
+    resolution: {integrity: sha1-WDsap3WWHUsROsF9nFC6753Xa9E=}
+    dependencies:
+      wrappy: 1.0.2
+    dev: false
+
+  /wrappy/1.0.2:
+    resolution: {integrity: sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8=}
+    dev: false
--- a/packages/build-utils/test/fixtures/28-pnpm-7/vercel.json
+++ b/packages/build-utils/test/fixtures/28-pnpm-7/vercel.json
@@ -0,0 +1,11 @@
+{
+  "version": 2,
+  "builds": [{ "src": "package.json", "use": "@vercel/static-build" }],
+  "probes": [
+    {
+      "path": "/",
+      "mustContain": "pnpm version: 7",
+      "logMustContain": "pnpm run build"
+    }
+  ]
+}
--- a/packages/build-utils/test/integration.test.ts
+++ b/packages/build-utils/test/integration.test.ts
@@ -32,6 +32,7 @@ const skipFixtures: string[] = [
  '08-zero-config-middleman',
  '21-npm-workspaces',
  '23-pnpm-workspaces',
+  '27-yarn-workspaces',
 ];

 // eslint-disable-next-line no-restricted-syntax
--- a/packages/build-utils/test/unit.detect-workspace-managers.test.ts
+++ b/packages/build-utils/test/unit.detect-workspace-managers.test.ts
@@ -0,0 +1,31 @@
+import path from 'path';
+import { detectFramework } from '../src/detect-framework';
+import workspaceManagers from '../src/workspaces/workspace-managers';
+import { FixtureFilesystem } from './utils/fixture-filesystem';
+
+describe('workspace-managers', () => {
+  describe.each([
+    ['npm', '21-npm-workspaces'],
+    ['pnpm', '23-pnpm-workspaces'],
+    ['yarn', '27-yarn-workspaces'],
+    ['yarn', '25-multiple-lock-files-yarn'],
+    ['pnpm', '26-multiple-lock-files-pnpm'],
+    [null, '22-pnpm'],
+  ])('with detectFramework', (frameworkSlug, fixturePath) => {
+    const testName = frameworkSlug
+      ? `should detect a ${frameworkSlug} workspace for ${fixturePath}`
+      : `should not detect framework for ${fixturePath}`;
+
+    it(testName, async () => {
+      const fixture = path.join(__dirname, 'fixtures', fixturePath);
+      const fs = new FixtureFilesystem(fixture);
+
+      const result = await detectFramework({
+        fs,
+        frameworkList: workspaceManagers,
+      });
+
+      expect(result).toBe(frameworkSlug);
+    });
+  });
+});
--- a/packages/build-utils/test/unit.framework-detector.test.ts
+++ b/packages/build-utils/test/unit.framework-detector.test.ts
@@ -1,21 +1,32 @@
+import path from 'path';
 import frameworkList from '@vercel/frameworks';
 import { detectFramework, DetectorFilesystem } from '../src';
+import { Stat } from '../src/detectors/filesystem';
+
+const posixPath = path.posix;

 class VirtualFilesystem extends DetectorFilesystem {
  private files: Map<string, Buffer>;
+  private cwd: string;

-  constructor(files: { [key: string]: string | Buffer }) {
+  constructor(files: { [key: string]: string | Buffer }, cwd = '') {
    super();
    this.files = new Map();
+    this.cwd = cwd;
    Object.entries(files).map(([key, value]) => {
      const buffer = typeof value === 'string' ? Buffer.from(value) : value;
      this.files.set(key, buffer);
    });
  }

-  async _hasPath(path: string): Promise<boolean> {
+  private _normalizePath(rawPath: string): string {
+    return posixPath.normalize(rawPath);
+  }
+
+  async _hasPath(name: string): Promise<boolean> {
+    const basePath = this._normalizePath(posixPath.join(this.cwd, name));
    for (const file of this.files.keys()) {
-      if (file.startsWith(path)) {
+      if (file.startsWith(basePath)) {
        return true;
      }
    }
@@ -24,11 +35,13 @@ class VirtualFilesystem extends DetectorFilesystem {
  }

  async _isFile(name: string): Promise<boolean> {
-    return this.files.has(name);
+    const basePath = this._normalizePath(posixPath.join(this.cwd, name));
+    return this.files.has(basePath);
  }

  async _readFile(name: string): Promise<Buffer> {
-    const file = this.files.get(name);
+    const basePath = this._normalizePath(posixPath.join(this.cwd, name));
+    const file = this.files.get(basePath);

    if (file === undefined) {
      throw new Error('File does not exist');
@@ -40,115 +53,291 @@ class VirtualFilesystem extends DetectorFilesystem {

    return file;
  }
+
+  /**
+   * An example of how to implement readdir for a virtual filesystem.
+   */
+  async _readdir(name = '/'): Promise<Stat[]> {
+    return (
+      [...this.files.keys()]
+        .map(filepath => {
+          const basePath = this._normalizePath(
+            posixPath.join(this.cwd, name === '/' ? '' : name)
+          );
+          const fileDirectoryName = posixPath.dirname(filepath);
+
+          if (fileDirectoryName === basePath) {
+            return {
+              name: posixPath.basename(filepath),
+              path: filepath.replace(
+                this.cwd === '' ? this.cwd : `${this.cwd}/`,
+                ''
+              ),
+              type: 'file',
+            };
+          }
+
+          if (
+            (basePath === '.' && fileDirectoryName !== '.') ||
+            fileDirectoryName.startsWith(basePath)
+          ) {
+            let subDirectoryName = fileDirectoryName.replace(
+              basePath === '.' ? '' : `${basePath}/`,
+              ''
+            );
+
+            if (subDirectoryName.includes('/')) {
+              subDirectoryName = subDirectoryName.split('/')[0];
+            }
+
+            return {
+              name: subDirectoryName,
+              path:
+                name === '/'
+                  ? subDirectoryName
+                  : this._normalizePath(posixPath.join(name, subDirectoryName)),
+              type: 'dir',
+            };
+          }
+
+          return null;
+        })
+        // remove nulls
+        .filter((stat): stat is Stat => stat !== null)
+        // remove duplicates
+        .filter(
+          (stat, index, self) =>
+            index ===
+            self.findIndex(s => s.name === stat.name && s.path === stat.path)
+        )
+    );
+  }
+
+  /**
+   * An example of how to implement chdir for a virtual filesystem.
+   */
+  _chdir(name: string): DetectorFilesystem {
+    const basePath = this._normalizePath(posixPath.join(this.cwd, name));
+    const files = Object.fromEntries(
+      [...this.files.keys()].map(key => [key, this.files.get(key) ?? ''])
+    );
+
+    return new VirtualFilesystem(files, basePath);
+  }
 }

-describe('#detectFramework', () => {
-  it('Do not detect anything', async () => {
-    const fs = new VirtualFilesystem({
-      'README.md': '# hi',
-      'api/cheese.js': 'export default (req, res) => res.end("cheese");',
-    });
+describe('DetectorFilesystem', () => {
+  it('should return the directory contents relative to the cwd', async () => {
+    const files = {
+      'package.json': '{}',
+      'packages/app1/package.json': '{}',
+      'packages/app2/package.json': '{}',
+    };

-    expect(await detectFramework({ fs, frameworkList })).toBe(null);
+    const fs = new VirtualFilesystem(files);
+
+    expect(await fs.readdir('/')).toEqual([
+      { name: 'package.json', path: 'package.json', type: 'file' },
+      { name: 'packages', path: 'packages', type: 'dir' },
+    ]);
+
+    expect(await fs.readdir('packages')).toEqual([
+      { name: 'app1', path: 'packages/app1', type: 'dir' },
+      { name: 'app2', path: 'packages/app2', type: 'dir' },
+    ]);
+
+    expect(await fs.readdir('./packages')).toEqual([
+      { name: 'app1', path: 'packages/app1', type: 'dir' },
+      { name: 'app2', path: 'packages/app2', type: 'dir' },
+    ]);
+
+    expect(await fs.readdir('packages/app1')).toEqual([
+      {
+        name: 'package.json',
+        path: 'packages/app1/package.json',
+        type: 'file',
+      },
+    ]);
  });

-  it('Detect Next.js', async () => {
-    const fs = new VirtualFilesystem({
-      'package.json': JSON.stringify({
-        dependencies: {
-          next: '9.0.0',
-        },
-      }),
+  it('should be able to change directories', async () => {
+    const nextPackageJson = JSON.stringify({
+      dependencies: {
+        next: '9.0.0',
+      },
+    });
+    const gatsbyPackageJson = JSON.stringify({
+      dependencies: {
+        gatsby: '1.0.0',
+      },
    });

-    expect(await detectFramework({ fs, frameworkList })).toBe('nextjs');
+    const files = {
+      'package.json': '{}',
+      'packages/app1/package.json': nextPackageJson,
+      'packages/app2/package.json': gatsbyPackageJson,
+    };
+
+    const fs = new VirtualFilesystem(files);
+    const packagesFs = fs.chdir('packages');
+
+    expect(await packagesFs.readdir('/')).toEqual([
+      { name: 'app1', path: 'app1', type: 'dir' },
+      { name: 'app2', path: 'app2', type: 'dir' },
+    ]);
+
+    expect(await packagesFs.hasPath('app1')).toBe(true);
+    expect(await packagesFs.hasPath('app3')).toBe(false);
+    expect(await packagesFs.isFile('app1')).toBe(false);
+    expect(await packagesFs.isFile('app2')).toBe(false);
+    expect(await packagesFs.isFile('app1/package.json')).toBe(true);
+    expect(await packagesFs.isFile('app2/package.json')).toBe(true);
+    expect(
+      await (await packagesFs.readFile('app1/package.json')).toString()
+    ).toEqual(nextPackageJson);
+    expect(
+      await (await packagesFs.readFile('app2/package.json')).toString()
+    ).toEqual(gatsbyPackageJson);
+
+    expect(await detectFramework({ fs: packagesFs, frameworkList })).toBe(null);
+
+    const nextAppFs = packagesFs.chdir('app1');
+
+    expect(await nextAppFs.readdir('/')).toEqual([
+      { name: 'package.json', path: 'package.json', type: 'file' },
+    ]);
+
+    expect(await (await nextAppFs.readFile('package.json')).toString()).toEqual(
+      nextPackageJson
+    );
+
+    expect(await detectFramework({ fs: nextAppFs, frameworkList })).toBe(
+      'nextjs'
+    );
+
+    const gatsbyAppFs = packagesFs.chdir('./app2');
+
+    expect(await gatsbyAppFs.readdir('/')).toEqual([
+      { name: 'package.json', path: 'package.json', type: 'file' },
+    ]);
+
+    expect(
+      await (await gatsbyAppFs.readFile('package.json')).toString()
+    ).toEqual(gatsbyPackageJson);
+
+    expect(await detectFramework({ fs: gatsbyAppFs, frameworkList })).toBe(
+      'gatsby'
+    );
  });

-  it('Detect Nuxt.js', async () => {
-    const fs = new VirtualFilesystem({
-      'package.json': JSON.stringify({
-        dependencies: {
-          nuxt: '1.0.0',
-        },
-      }),
+  describe('#detectFramework', () => {
+    it('Do not detect anything', async () => {
+      const fs = new VirtualFilesystem({
+        'README.md': '# hi',
+        'api/cheese.js': 'export default (req, res) => res.end("cheese");',
+      });
+
+      expect(await detectFramework({ fs, frameworkList })).toBe(null);
    });

-    expect(await detectFramework({ fs, frameworkList })).toBe('nuxtjs');
-  });
+    it('Detect Next.js', async () => {
+      const fs = new VirtualFilesystem({
+        'package.json': JSON.stringify({
+          dependencies: {
+            next: '9.0.0',
+          },
+        }),
+      });

-  it('Detect Gatsby', async () => {
-    const fs = new VirtualFilesystem({
-      'package.json': JSON.stringify({
-        dependencies: {
-          gatsby: '1.0.0',
-        },
-      }),
+      expect(await detectFramework({ fs, frameworkList })).toBe('nextjs');
    });

-    expect(await detectFramework({ fs, frameworkList })).toBe('gatsby');
-  });
+    it('Detect Nuxt.js', async () => {
+      const fs = new VirtualFilesystem({
+        'package.json': JSON.stringify({
+          dependencies: {
+            nuxt: '1.0.0',
+          },
+        }),
+      });

-  it('Detect Hugo #1', async () => {
-    const fs = new VirtualFilesystem({
-      'config.yaml': 'baseURL: http://example.org/',
-      'content/post.md': '# hello world',
+      expect(await detectFramework({ fs, frameworkList })).toBe('nuxtjs');
    });

-    expect(await detectFramework({ fs, frameworkList })).toBe('hugo');
-  });
+    it('Detect Gatsby', async () => {
+      const fs = new VirtualFilesystem({
+        'package.json': JSON.stringify({
+          dependencies: {
+            gatsby: '1.0.0',
+          },
+        }),
+      });

-  it('Detect Hugo #2', async () => {
-    const fs = new VirtualFilesystem({
-      'config.json': '{ "baseURL": "http://example.org/" }',
-      'content/post.md': '# hello world',
+      expect(await detectFramework({ fs, frameworkList })).toBe('gatsby');
    });

-    expect(await detectFramework({ fs, frameworkList })).toBe('hugo');
-  });
+    it('Detect Hugo #1', async () => {
+      const fs = new VirtualFilesystem({
+        'config.yaml': 'baseURL: http://example.org/',
+        'content/post.md': '# hello world',
+      });

-  it('Detect Hugo #3', async () => {
-    const fs = new VirtualFilesystem({
-      'config.toml': 'baseURL = "http://example.org/"',
-      'content/post.md': '# hello world',
+      expect(await detectFramework({ fs, frameworkList })).toBe('hugo');
    });

-    expect(await detectFramework({ fs, frameworkList })).toBe('hugo');
-  });
+    it('Detect Hugo #2', async () => {
+      const fs = new VirtualFilesystem({
+        'config.json': '{ "baseURL": "http://example.org/" }',
+        'content/post.md': '# hello world',
+      });

-  it('Detect Jekyll', async () => {
-    const fs = new VirtualFilesystem({
-      '_config.yml': 'config',
+      expect(await detectFramework({ fs, frameworkList })).toBe('hugo');
    });

-    expect(await detectFramework({ fs, frameworkList })).toBe('jekyll');
-  });
+    it('Detect Hugo #3', async () => {
+      const fs = new VirtualFilesystem({
+        'config.toml': 'baseURL = "http://example.org/"',
+        'content/post.md': '# hello world',
+      });

-  it('Detect Middleman', async () => {
-    const fs = new VirtualFilesystem({
-      'config.rb': 'config',
+      expect(await detectFramework({ fs, frameworkList })).toBe('hugo');
    });

-    expect(await detectFramework({ fs, frameworkList })).toBe('middleman');
-  });
+    it('Detect Jekyll', async () => {
+      const fs = new VirtualFilesystem({
+        '_config.yml': 'config',
+      });

-  it('Detect Scully', async () => {
-    const fs = new VirtualFilesystem({
-      'package.json': JSON.stringify({
-        dependencies: {
-          '@angular/cli': 'latest',
-          '@scullyio/init': 'latest',
-        },
-      }),
+      expect(await detectFramework({ fs, frameworkList })).toBe('jekyll');
    });

-    expect(await detectFramework({ fs, frameworkList })).toBe('scully');
-  });
+    it('Detect Middleman', async () => {
+      const fs = new VirtualFilesystem({
+        'config.rb': 'config',
+      });

-  it('Detect Zola', async () => {
-    const fs = new VirtualFilesystem({
-      'config.toml': 'base_url = "/"',
+      expect(await detectFramework({ fs, frameworkList })).toBe('middleman');
    });

-    expect(await detectFramework({ fs, frameworkList })).toBe('zola');
+    it('Detect Scully', async () => {
+      const fs = new VirtualFilesystem({
+        'package.json': JSON.stringify({
+          dependencies: {
+            '@angular/cli': 'latest',
+            '@scullyio/init': 'latest',
+          },
+        }),
+      });
+
+      expect(await detectFramework({ fs, frameworkList })).toBe('scully');
+    });
+
+    it('Detect Zola', async () => {
+      const fs = new VirtualFilesystem({
+        'config.toml': 'base_url = "/"',
+      });
+
+      expect(await detectFramework({ fs, frameworkList })).toBe('zola');
+    });
  });
 });
--- a/packages/build-utils/test/unit.get-env-for-package-manager.test.ts
+++ b/packages/build-utils/test/unit.get-env-for-package-manager.test.ts
@@ -1,16 +1,17 @@
 import assert from 'assert';
-import { getEnvForPackageManager, NodeVersion } from '../src';
-import { CliType } from '../src/fs/run-user-scripts';
+import { getEnvForPackageManager } from '../src';

 describe('Test `getEnvForPackageManager()`', () => {
-  const cases = [
+  const cases: Array<{
+    name: string;
+    args: Parameters<typeof getEnvForPackageManager>[0];
+    want: unknown;
+  }> = [
    {
      name: 'should do nothing to env for npm < 6 and node < 16',
      args: {
-        cliType: 'npm' as CliType,
-        nodeVersion: {
-          major: 14,
-        } as NodeVersion,
+        cliType: 'npm',
+        nodeVersion: { major: 14, range: '14.x', runtime: 'nodejs14.x' },
        lockfileVersion: 1,
        env: {
          FOO: 'bar',
@@ -23,10 +24,8 @@ describe('Test `getEnvForPackageManager()`', () => {
    {
      name: 'should set path if npm 7+ is detected and node < 16',
      args: {
-        cliType: 'npm' as CliType,
-        nodeVersion: {
-          major: 14,
-        } as NodeVersion,
+        cliType: 'npm',
+        nodeVersion: { major: 14, range: '14.x', runtime: 'nodejs14.x' },
        lockfileVersion: 2,
        env: {
          FOO: 'bar',
@@ -41,10 +40,8 @@ describe('Test `getEnvForPackageManager()`', () => {
    {
      name: 'should not set path if node is 16 and npm 7+ is detected',
      args: {
-        cliType: 'npm' as CliType,
-        nodeVersion: {
-          major: 16,
-        } as NodeVersion,
+        cliType: 'npm',
+        nodeVersion: { major: 16, range: '16.x', runtime: 'nodejs16.x' },
        lockfileVersion: 2,
        env: {
          FOO: 'bar',
@@ -59,10 +56,8 @@ describe('Test `getEnvForPackageManager()`', () => {
    {
      name: 'should set YARN_NODE_LINKER w/yarn if it is not already defined',
      args: {
-        cliType: 'yarn' as CliType,
-        nodeVersion: {
-          major: 16,
-        } as NodeVersion,
+        cliType: 'yarn',
+        nodeVersion: { major: 16, range: '16.x', runtime: 'nodejs16.x' },
        lockfileVersion: 2,
        env: {
          FOO: 'bar',
@@ -76,10 +71,8 @@ describe('Test `getEnvForPackageManager()`', () => {
    {
      name: 'should not set YARN_NODE_LINKER if it already exists',
      args: {
-        cliType: 'yarn' as CliType,
-        nodeVersion: {
-          major: 16,
-        } as NodeVersion,
+        cliType: 'yarn',
+        nodeVersion: { major: 16, range: '16.x', runtime: 'nodejs16.x' },
        lockfileVersion: 2,
        env: {
          FOO: 'bar',
@@ -91,6 +84,50 @@ describe('Test `getEnvForPackageManager()`', () => {
        YARN_NODE_LINKER: 'exists',
      },
    },
+    {
+      name: 'should set path if pnpm 7+ is detected and Node version is greater than 12',
+      args: {
+        cliType: 'pnpm',
+        nodeVersion: { major: 16, range: '16.x', runtime: 'nodejs16.x' },
+        lockfileVersion: 5.4,
+        env: {
+          FOO: 'bar',
+          PATH: 'foo',
+        },
+      },
+      want: {
+        FOO: 'bar',
+        PATH: '/pnpm7/pnpm:foo',
+      },
+    },
+    {
+      name: 'should not set path if pnpm 7+ is detected and Node version is less than or equal to 12',
+      args: {
+        cliType: 'pnpm',
+        nodeVersion: { major: 12, range: '12.x', runtime: 'nodejs12.x' },
+        lockfileVersion: 5.4,
+        env: {
+          FOO: 'bar',
+        },
+      },
+      want: {
+        FOO: 'bar',
+      },
+    },
+    {
+      name: 'should not set path if pnpm 6 is detected',
+      args: {
+        cliType: 'pnpm',
+        nodeVersion: { major: 14, range: '14.x', runtime: 'nodejs14.x' },
+        lockfileVersion: 5.3,
+        env: {
+          FOO: 'bar',
+        },
+      },
+      want: {
+        FOO: 'bar',
+      },
+    },
  ];

  for (const { name, want, args } of cases) {
--- a/packages/build-utils/test/unit.test.ts
+++ b/packages/build-utils/test/unit.test.ts
@@ -15,6 +15,7 @@ import {
  runPackageJsonScript,
  scanParentDirs,
  FileBlob,
+  Meta,
 } from '../src';

 async function expectBuilderError(promise: Promise<any>, pattern: string) {
@@ -175,9 +176,13 @@ it('should only match supported node versions, otherwise throw an error', async
    'major',
    14
  );
+  expect(await getSupportedNodeVersion('16.x', false)).toHaveProperty(
+    'major',
+    16
+  );

  const autoMessage =
-    'Please set Node.js Version to 14.x in your Project Settings to use Node.js 14.';
+    'Please set Node.js Version to 16.x in your Project Settings to use Node.js 16.';
  await expectBuilderError(
    getSupportedNodeVersion('8.11.x', true),
    autoMessage
@@ -195,9 +200,13 @@ it('should only match supported node versions, otherwise throw an error', async
    'major',
    14
  );
+  expect(await getSupportedNodeVersion('16.x', true)).toHaveProperty(
+    'major',
+    16
+  );

  const foundMessage =
-    'Please set "engines": { "node": "14.x" } in your `package.json` file to use Node.js 14.';
+    'Please set "engines": { "node": "16.x" } in your `package.json` file to use Node.js 16.';
  await expectBuilderError(
    getSupportedNodeVersion('8.11.x', false),
    foundMessage
@@ -218,8 +227,8 @@ it('should match all semver ranges', async () => {
  // See https://docs.npmjs.com/files/package.json#engines
  expect(await getSupportedNodeVersion('12.0.0')).toHaveProperty('major', 12);
  expect(await getSupportedNodeVersion('12.x')).toHaveProperty('major', 12);
-  expect(await getSupportedNodeVersion('>=10')).toHaveProperty('major', 14);
-  expect(await getSupportedNodeVersion('>=10.3.0')).toHaveProperty('major', 14);
+  expect(await getSupportedNodeVersion('>=10')).toHaveProperty('major', 16);
+  expect(await getSupportedNodeVersion('>=10.3.0')).toHaveProperty('major', 16);
  expect(await getSupportedNodeVersion('11.5.0 - 12.5.0')).toHaveProperty(
    'major',
    12
@@ -230,6 +239,10 @@ it('should match all semver ranges', async () => {
  );
  expect(await getSupportedNodeVersion('~12.5.0')).toHaveProperty('major', 12);
  expect(await getSupportedNodeVersion('^12.5.0')).toHaveProperty('major', 12);
+  expect(await getSupportedNodeVersion('12.5.0 - 14.5.0')).toHaveProperty(
+    'major',
+    14
+  );
 });

 it('should ignore node version in vercel dev getNodeVersion()', async () => {
@@ -245,8 +258,8 @@ it('should ignore node version in vercel dev getNodeVersion()', async () => {

 it('should select project setting from config when no package.json is found', async () => {
  expect(
-    await getNodeVersion('/tmp', undefined, { nodeVersion: '14.x' }, {})
-  ).toHaveProperty('range', '14.x');
+    await getNodeVersion('/tmp', undefined, { nodeVersion: '16.x' }, {})
+  ).toHaveProperty('range', '16.x');
  expect(warningMessages).toStrictEqual([]);
 });

@@ -277,7 +290,7 @@ it('should not warn when package.json engines matches project setting from confi
 });

 it('should get latest node version', async () => {
-  expect(getLatestNodeVersion()).toHaveProperty('major', 14);
+  expect(getLatestNodeVersion()).toHaveProperty('major', 16);
 });

 it('should throw for discontinued versions', async () => {
@@ -312,8 +325,8 @@ it('should warn for deprecated versions, soon to be discontinued', async () => {
    10
  );
  expect(warningMessages).toStrictEqual([
-    'Error: Node.js version 10.x is deprecated. Deployments created on or after 2021-04-20 will fail to build. Please set "engines": { "node": "14.x" } in your `package.json` file to use Node.js 14. This change is the result of a decision made by an upstream infrastructure provider (AWS).',
-    'Error: Node.js version 10.x is deprecated. Deployments created on or after 2021-04-20 will fail to build. Please set Node.js Version to 14.x in your Project Settings to use Node.js 14. This change is the result of a decision made by an upstream infrastructure provider (AWS).',
+    'Error: Node.js version 10.x is deprecated. Deployments created on or after 2021-04-20 will fail to build. Please set "engines": { "node": "16.x" } in your `package.json` file to use Node.js 16. This change is the result of a decision made by an upstream infrastructure provider (AWS).',
+    'Error: Node.js version 10.x is deprecated. Deployments created on or after 2021-04-20 will fail to build. Please set Node.js Version to 16.x in your Project Settings to use Node.js 16. This change is the result of a decision made by an upstream infrastructure provider (AWS).',
  ]);

  global.Date.now = realDateNow;
@@ -413,3 +426,39 @@ it('should detect pnpm Workspaces', async () => {
  expect(result.cliType).toEqual('pnpm');
  expect(result.lockfileVersion).toEqual(5.3);
 });
+
+it('should only invoke `runNpmInstall()` once per `package.json` file (serial)', async () => {
+  const meta: Meta = {};
+  const fixture = path.join(__dirname, 'fixtures', '02-zero-config-api');
+  const apiDir = path.join(fixture, 'api');
+  const run1 = await runNpmInstall(apiDir, [], undefined, meta);
+  expect(run1).toEqual(true);
+  expect(
+    (meta.runNpmInstallSet as Set<string>).has(
+      path.join(fixture, 'package.json')
+    )
+  ).toEqual(true);
+  const run2 = await runNpmInstall(apiDir, [], undefined, meta);
+  expect(run2).toEqual(false);
+  const run3 = await runNpmInstall(fixture, [], undefined, meta);
+  expect(run3).toEqual(false);
+});
+
+it('should only invoke `runNpmInstall()` once per `package.json` file (parallel)', async () => {
+  const meta: Meta = {};
+  const fixture = path.join(__dirname, 'fixtures', '02-zero-config-api');
+  const apiDir = path.join(fixture, 'api');
+  const [run1, run2, run3] = await Promise.all([
+    runNpmInstall(apiDir, [], undefined, meta),
+    runNpmInstall(apiDir, [], undefined, meta),
+    runNpmInstall(fixture, [], undefined, meta),
+  ]);
+  expect(run1).toEqual(true);
+  expect(run2).toEqual(false);
+  expect(run3).toEqual(false);
+  expect(
+    (meta.runNpmInstallSet as Set<string>).has(
+      path.join(fixture, 'package.json')
+    )
+  ).toEqual(true);
+});
--- a/packages/build-utils/test/utils/fixture-filesystem.ts
+++ b/packages/build-utils/test/utils/fixture-filesystem.ts
@@ -0,0 +1,51 @@
+import { promises } from 'fs';
+import path from 'path';
+
+import { DetectorFilesystem } from '../../src';
+import { Stat } from '../../src/detectors/filesystem';
+
+const { stat, readFile, readdir } = promises;
+
+export class FixtureFilesystem extends DetectorFilesystem {
+  private rootPath: string;
+
+  constructor(fixturePath: string) {
+    super();
+
+    this.rootPath = fixturePath;
+  }
+
+  async _hasPath(name: string): Promise<boolean> {
+    try {
+      const filePath = path.join(this.rootPath, name);
+      await stat(filePath);
+
+      return true;
+    } catch {
+      return false;
+    }
+  }
+  async _readFile(name: string): Promise<Buffer> {
+    const filePath = path.join(this.rootPath, name);
+    return readFile(filePath);
+  }
+  async _isFile(name: string): Promise<boolean> {
+    const filePath = path.join(this.rootPath, name);
+    return (await stat(filePath)).isFile();
+  }
+
+  async _readdir(name: string): Promise<Stat[]> {
+    const dirPath = path.join(this.rootPath, name);
+    const files = await readdir(dirPath, { withFileTypes: true });
+
+    return files.map(file => ({
+      name: file.name,
+      type: file.isFile() ? 'file' : 'dir',
+      path: path.join(name, file.name),
+    }));
+  }
+
+  _chdir(name: string): DetectorFilesystem {
+    return new FixtureFilesystem(path.join(this.rootPath, name));
+  }
+}
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -1,6 +1,6 @@
 {
  "name": "vercel",
-  "version": "24.1.0",
+  "version": "24.2.2-canary.0",
  "preferGlobal": true,
  "license": "Apache-2.0",
  "description": "The command-line interface for Vercel",
@@ -43,14 +43,15 @@
    "node": ">= 12"
  },
  "dependencies": {
-    "@vercel/build-utils": "2.15.1",
-    "@vercel/go": "1.3.2",
-    "@vercel/node": "1.14.1",
-    "@vercel/python": "2.2.2",
-    "@vercel/ruby": "1.3.2",
+    "@vercel/build-utils": "2.17.0",
+    "@vercel/go": "1.4.1",
+    "@vercel/node": "1.15.1",
+    "@vercel/python": "2.3.1",
+    "@vercel/ruby": "1.3.4",
    "update-notifier": "4.1.0"
  },
  "devDependencies": {
+    "@alex_neo/jest-expect-message": "1.0.5",
    "@next/env": "11.1.2",
    "@sentry/node": "5.5.0",
    "@sindresorhus/slugify": "0.11.0",
@@ -68,7 +69,8 @@
    "@types/glob": "7.1.1",
    "@types/http-proxy": "1.16.2",
    "@types/inquirer": "7.3.1",
-    "@types/jest": "27.0.1",
+    "@types/jest": "27.4.1",
+    "@types/jest-expect-message": "1.0.3",
    "@types/load-json-file": "2.0.7",
    "@types/mime-types": "2.1.0",
    "@types/minimatch": "3.0.3",
@@ -88,11 +90,9 @@
    "@types/update-notifier": "5.1.0",
    "@types/which": "1.3.2",
    "@types/write-json-file": "2.2.1",
-    "@vercel/client": "10.4.1",
-    "@vercel/fetch-retry": "5.0.3",
-    "@vercel/frameworks": "0.7.1",
+    "@vercel/client": "11.0.1",
+    "@vercel/frameworks": "0.9.0",
    "@vercel/ncc": "0.24.0",
-    "@vercel/nft": "0.17.5",
    "@zeit/fun": "0.11.2",
    "@zeit/source-map-support": "0.6.2",
    "ajv": "6.12.2",
@@ -177,6 +177,9 @@
        "isolatedModules": true
      }
    },
+    "setupFilesAfterEnv": [
+      "@alex_neo/jest-expect-message"
+    ],
    "verbose": false,
    "testEnvironment": "node",
    "testMatch": [
--- a/packages/cli/src/commands/alias/set.ts
+++ b/packages/cli/src/commands/alias/set.ts
@@ -73,7 +73,7 @@ export default async function set(
  if (args.length === 0) {
    output.error(
      `To ship to production, optionally configure your domains (${link(
-        'https://vercel.com/docs/v2/custom-domains'
+        'https://vercel.link/domain-configuration'
      )}) and run ${getCommandName(`--prod`)}.`
    );
    return 1;
--- a/packages/cli/src/commands/deploy/index.ts
+++ b/packages/cli/src/commands/deploy/index.ts
@@ -61,6 +61,8 @@ import { getPreferredPreviewURL } from '../../util/deploy/get-preferred-preview-
 import { Output } from '../../util/output';
 import { help } from './args';
 import { getDeploymentChecks } from '../../util/deploy/get-deployment-checks';
+import parseTarget from '../../util/deploy/parse-target';
+import getPrebuiltJson from '../../util/deploy/get-prebuilt-json';

 export default async (client: Client) => {
  const { output } = client;
@@ -155,7 +157,7 @@ export default async (client: Client) => {
    }
  }

-  const { log, debug, error, warn, isTTY } = output;
+  const { log, debug, error, prettyError, isTTY } = output;

  const quiet = !isTTY;

@@ -181,6 +183,46 @@ export default async (client: Client) => {
    );
  }

+  // build `target`
+  const target = parseTarget(output, argv['--target'], argv['--prod']);
+  if (typeof target === 'number') {
+    return target;
+  }
+
+  // build `--prebuilt`
+  if (argv['--prebuilt']) {
+    const prebuiltExists = await fs.pathExists(join(path, '.vercel/output'));
+    if (!prebuiltExists) {
+      error(
+        `The ${param(
+          '--prebuilt'
+        )} option was used, but no prebuilt output found in ".vercel/output". Run ${getCommandName(
+          'build'
+        )} to generate a local build.`
+      );
+      return 1;
+    }
+
+    const prebuiltBuild = await getPrebuiltJson(path);
+    const assumedTarget = target || 'preview';
+    if (prebuiltBuild?.target && prebuiltBuild.target !== assumedTarget) {
+      let specifyTarget = '';
+      if (prebuiltBuild.target === 'production') {
+        specifyTarget = ` --prod`;
+      }
+
+      prettyError({
+        message: `The ${param(
+          '--prebuilt'
+        )} option was used with the target environment "${assumedTarget}", but the prebuilt output found in ".vercel/output" was built with target environment "${
+          prebuiltBuild.target
+        }". Please run ${getCommandName(`--prebuilt${specifyTarget}`)}.`,
+        link: 'https://vercel.link/prebuilt-environment-mismatch',
+      });
+      return 1;
+    }
+  }
+
  // retrieve `project` and `org` from .vercel
  const link = await getLinkedProject(client, path);

@@ -403,33 +445,6 @@ export default async (client: Client) => {
    .filter(Boolean);
  const regions = regionFlag.length > 0 ? regionFlag : localConfig.regions;

-  // build `target`
-  let target;
-  if (argv['--target']) {
-    const deprecatedTarget = argv['--target'];
-
-    if (!['staging', 'production'].includes(deprecatedTarget)) {
-      error(
-        `The specified ${param('--target')} ${code(
-          deprecatedTarget
-        )} is not valid`
-      );
-      return 1;
-    }
-
-    if (deprecatedTarget === 'production') {
-      warn(
-        'We recommend using the much shorter `--prod` option instead of `--target production` (deprecated)'
-      );
-    }
-
-    output.debug(`Setting target to ${deprecatedTarget}`);
-    target = deprecatedTarget;
-  } else if (argv['--prod']) {
-    output.debug('Setting target to production');
-    target = 'production';
-  }
-
  const currentTeam = org?.type === 'team' ? org.id : undefined;
  const now = new Now({
    client,
--- a/packages/cli/src/commands/dev/dev.ts
+++ b/packages/cli/src/commands/dev/dev.ts
@@ -10,6 +10,8 @@ import { ProjectSettings } from '../../types';
 import getDecryptedEnvRecords from '../../util/get-decrypted-env-records';
 import setupAndLink from '../../util/link/setup-and-link';
 import getSystemEnvValues from '../../util/env/get-system-env-values';
+import { getCommandName } from '../../util/pkg-name';
+import param from '../../util/output/param';

 type Options = {
  '--listen': string;
@@ -46,6 +48,13 @@ export default async function dev(
  }

  if (link.status === 'error') {
+    if (link.reason === 'HEADLESS') {
+      client.output.error(
+        `Command ${getCommandName(
+          'dev'
+        )} requires confirmation. Use option ${param('--confirm')} to confirm.`
+      );
+    }
    return link.exitCode;
  }

@@ -82,7 +91,7 @@ export default async function dev(
    }

    [{ envs: projectEnvs }, { systemEnvValues }] = await Promise.all([
-      getDecryptedEnvRecords(output, client, project.id),
+      getDecryptedEnvRecords(output, client, project.id, 'vercel-cli:dev'),
      project.autoExposeSystemEnvs
        ? getSystemEnvValues(output, client, project.id)
        : { systemEnvValues: [] },
--- a/packages/cli/src/commands/env/add.ts
+++ b/packages/cli/src/commands/env/add.ts
@@ -79,7 +79,12 @@ export default async function add(
    }
  }

-  const { envs } = await getEnvRecords(output, client, project.id);
+  const { envs } = await getEnvRecords(
+    output,
+    client,
+    project.id,
+    'vercel-cli:env:add'
+  );
  const existing = new Set(
    envs.filter(r => r.key === envName).map(r => r.target)
  );
--- a/packages/cli/src/commands/env/index.ts
+++ b/packages/cli/src/commands/env/index.ts
@@ -115,9 +115,11 @@ export default async function main(client: Client) {
    return 2;
  }

-  const { subcommand, args } = getSubcommand(argv._.slice(1), COMMAND_CONFIG);
+  const cwd = argv['--cwd'] || process.cwd();
+  const subArgs = argv._.slice(1);
+  const { subcommand, args } = getSubcommand(subArgs, COMMAND_CONFIG);
  const { output, config } = client;
-  const link = await getLinkedProject(client);
+  const link = await getLinkedProject(client, cwd);
  if (link.status === 'error') {
    return link.exitCode;
  } else if (link.status === 'not_linked') {
@@ -144,7 +146,9 @@ export default async function main(client: Client) {
          ProjectEnvTarget.Development,
          argv,
          args,
-          output
+          output,
+          cwd,
+          'vercel-cli:env:pull'
        );
      default:
        output.error(getInvalidSubcommand(COMMAND_CONFIG));
--- a/packages/cli/src/commands/env/ls.ts
+++ b/packages/cli/src/commands/env/ls.ts
@@ -48,10 +48,16 @@ export default async function ls(

  const lsStamp = stamp();

-  const { envs } = await getEnvRecords(output, client, project.id, {
-    target: envTarget,
-    gitBranch: envGitBranch,
-  });
+  const { envs } = await getEnvRecords(
+    output,
+    client,
+    project.id,
+    'vercel-cli:env:ls',
+    {
+      target: envTarget,
+      gitBranch: envGitBranch,
+    }
+  );

  if (envs.length === 0) {
    output.log(
--- a/packages/cli/src/commands/env/pull.ts
+++ b/packages/cli/src/commands/env/pull.ts
@@ -1,5 +1,6 @@
 import chalk from 'chalk';
-import { closeSync, openSync, promises, readSync } from 'fs';
+import { outputFile } from 'fs-extra';
+import { closeSync, openSync, readSync } from 'fs';
 import { resolve } from 'path';
 import { Project, ProjectEnvTarget } from '../../types';
 import Client from '../../util/client';
@@ -12,7 +13,7 @@ import { Output } from '../../util/output';
 import param from '../../util/output/param';
 import stamp from '../../util/output/stamp';
 import { getCommandName } from '../../util/pkg-name';
-const { writeFile } = promises;
+import { EnvRecordsSource } from '../../util/env/get-env-records';

 const CONTENTS_PREFIX = '# Created by Vercel CLI\n';

@@ -49,7 +50,8 @@ export default async function pull(
  opts: Partial<Options>,
  args: string[],
  output: Output,
-  cwd: string = process.cwd()
+  cwd: string,
+  source: Extract<EnvRecordsSource, 'vercel-cli:env:pull' | 'vercel-cli:pull'>
 ) {
  if (args.length > 1) {
    output.error(
@@ -81,7 +83,7 @@ export default async function pull(
  }

  output.print(
-    `Downloading Development Environment Variables for Project ${chalk.bold(
+    `Downloading "${environment}" Environment Variables for Project ${chalk.bold(
      project.name
    )}\n`
  );
@@ -90,7 +92,7 @@ export default async function pull(
  output.spinner('Downloading');

  const [{ envs: projectEnvs }, { systemEnvValues }] = await Promise.all([
-    getDecryptedEnvRecords(output, client, project.id, environment),
+    getDecryptedEnvRecords(output, client, project.id, source, environment),
    project.autoExposeSystemEnvs
      ? getSystemEnvValues(output, client, project.id)
      : { systemEnvValues: [] },
@@ -99,7 +101,9 @@ export default async function pull(
  const records = exposeSystemEnvs(
    projectEnvs,
    systemEnvValues,
-    project.autoExposeSystemEnvs
+    project.autoExposeSystemEnvs,
+    undefined,
+    environment
  );

  const contents =
@@ -109,7 +113,7 @@ export default async function pull(
      .join('\n') +
    '\n';

-  await writeFile(fullPath, contents, 'utf8');
+  await outputFile(fullPath, contents, 'utf8');

  output.print(
    `${prependEmoji(
--- a/packages/cli/src/commands/env/rm.ts
+++ b/packages/cli/src/commands/env/rm.ts
@@ -67,10 +67,16 @@ export default async function rm(
    return 1;
  }

-  const result = await getEnvRecords(output, client, project.id, {
-    target: envTarget,
-    gitBranch: envGitBranch,
-  });
+  const result = await getEnvRecords(
+    output,
+    client,
+    project.id,
+    'vercel-cli:env:rm',
+    {
+      target: envTarget,
+      gitBranch: envGitBranch,
+    }
+  );

  let envs = result.envs.filter(env => env.key === envName);

--- a/packages/cli/src/commands/link/index.ts
+++ b/packages/cli/src/commands/link/index.ts
@@ -4,6 +4,8 @@ import getArgs from '../../util/get-args';
 import logo from '../../util/output/logo';
 import { getPkgName } from '../../util/pkg-name';
 import setupAndLink from '../../util/link/setup-and-link';
+import { getCommandName } from '../../util/pkg-name';
+import param from '../../util/output/param';

 const help = () => {
  console.log(`
@@ -67,6 +69,13 @@ export default async function main(client: Client) {
  });

  if (link.status === 'error') {
+    if (link.reason === 'HEADLESS') {
+      client.output.error(
+        `Command ${getCommandName(
+          'link'
+        )} requires confirmation. Use option ${param('--confirm')} to confirm.`
+      );
+    }
    return link.exitCode;
  } else if (link.status === 'not_linked') {
    // User aborted project linking questions
--- a/packages/cli/src/commands/pull.ts
+++ b/packages/cli/src/commands/pull.ts
@@ -4,7 +4,6 @@ import Client from '../util/client';
 import { ProjectEnvTarget } from '../types';
 import { emoji, prependEmoji } from '../util/emoji';
 import getArgs from '../util/get-args';
-import handleError from '../util/handle-error';
 import setupAndLink from '../util/link/setup-and-link';
 import logo from '../util/output/logo';
 import stamp from '../util/output/stamp';
@@ -16,7 +15,8 @@ import {
 } from '../util/projects/link';
 import { writeProjectSettings } from '../util/projects/project-settings';
 import envPull from './env/pull';
-
+import { getCommandName } from '../util/pkg-name';
+import param from '../util/output/param';
 import type { Project, Org } from '../types';
 import {
  isValidEnvTarget,
@@ -69,19 +69,14 @@ function processArgs(client: Client) {
 }

 function parseArgs(client: Client) {
-  try {
-    const argv = processArgs(client);
+  const argv = processArgs(client);

-    if (argv['--help']) {
-      help();
-      return 2;
-    }
-
-    return argv;
-  } catch (err) {
-    handleError(err);
-    return 1;
+  if (argv['--help']) {
+    help();
+    return 2;
  }
+
+  return argv;
 }

 type LinkResult = {
@@ -108,6 +103,13 @@ async function ensureLink(
  }

  if (link.status === 'error') {
+    if (link.reason === 'HEADLESS') {
+      client.output.error(
+        `Command ${getCommandName(
+          'pull'
+        )} requires confirmation. Use option ${param('--yes')} to confirm.`
+      );
+    }
    return link.exitCode;
  }

@@ -129,7 +131,8 @@ async function pullAllEnvFiles(
    argv,
    [join('.vercel', environmentFile)],
    client.output,
-    cwd
+    cwd,
+    'vercel-cli:pull'
  );
 }

--- a/packages/cli/src/index.ts
+++ b/packages/cli/src/index.ts
@@ -82,7 +82,12 @@ let debug: (s: string) => void = () => {};
 let apiUrl = 'https://api.vercel.com';

 const main = async () => {
-  const { isTTY } = process.stdout;
+  let { isTTY } = process.stdout;
+  if (process.env.FORCE_TTY === '1') {
+    isTTY = true;
+    process.stdout.isTTY = true;
+    process.stdin.isTTY = true;
+  }

  let argv;

@@ -585,73 +590,73 @@ const main = async () => {
    let func: any;
    switch (targetCommand) {
      case 'alias':
-        func = await import('./commands/alias');
+        func = require('./commands/alias').default;
        break;
      case 'billing':
-        func = await import('./commands/billing');
+        func = require('./commands/billing').default;
        break;
      case 'bisect':
-        func = await import('./commands/bisect');
+        func = require('./commands/bisect').default;
        break;
      case 'certs':
-        func = await import('./commands/certs');
+        func = require('./commands/certs').default;
        break;
      case 'deploy':
-        func = await import('./commands/deploy');
+        func = require('./commands/deploy').default;
        break;
      case 'dev':
-        func = await import('./commands/dev');
+        func = require('./commands/dev').default;
        break;
      case 'dns':
-        func = await import('./commands/dns');
+        func = require('./commands/dns').default;
        break;
      case 'domains':
-        func = await import('./commands/domains');
+        func = require('./commands/domains').default;
        break;
      case 'env':
-        func = await import('./commands/env');
+        func = require('./commands/env').default;
        break;
      case 'init':
-        func = await import('./commands/init');
+        func = require('./commands/init').default;
        break;
      case 'inspect':
-        func = await import('./commands/inspect');
+        func = require('./commands/inspect').default;
        break;
      case 'link':
-        func = await import('./commands/link');
+        func = require('./commands/link').default;
        break;
      case 'list':
-        func = await import('./commands/list');
+        func = require('./commands/list').default;
        break;
      case 'logs':
-        func = await import('./commands/logs');
+        func = require('./commands/logs').default;
        break;
      case 'login':
-        func = await import('./commands/login');
+        func = require('./commands/login').default;
        break;
      case 'logout':
-        func = await import('./commands/logout');
+        func = require('./commands/logout').default;
        break;
      case 'projects':
-        func = await import('./commands/projects');
+        func = require('./commands/projects').default;
        break;
      case 'pull':
-        func = await import('./commands/pull');
+        func = require('./commands/pull').default;
        break;
      case 'remove':
-        func = await import('./commands/remove');
+        func = require('./commands/remove').default;
        break;
      case 'secrets':
-        func = await import('./commands/secrets');
+        func = require('./commands/secrets').default;
        break;
      case 'teams':
-        func = await import('./commands/teams');
+        func = require('./commands/teams').default;
        break;
      case 'update':
-        func = await import('./commands/update');
+        func = require('./commands/update').default;
        break;
      case 'whoami':
-        func = await import('./commands/whoami');
+        func = require('./commands/whoami').default;
        break;
      default:
        func = null;
--- a/packages/cli/src/types.ts
+++ b/packages/cli/src/types.ts
@@ -277,7 +277,17 @@ export interface PaginationOptions {
 export type ProjectLinkResult =
  | { status: 'linked'; org: Org; project: Project }
  | { status: 'not_linked'; org: null; project: null }
-  | { status: 'error'; exitCode: number };
+  | {
+      status: 'error';
+      exitCode: number;
+      reason?:
+        | 'HEADLESS'
+        | 'NOT_AUTHORIZED'
+        | 'TEAM_DELETED'
+        | 'PATH_IS_FILE'
+        | 'INVALID_ROOT_DIRECTORY'
+        | 'MISSING_PROJECT_SETTINGS';
+    };

 export interface Token {
  id: string;
--- a/packages/cli/src/util/deploy/get-prebuilt-json.ts
+++ b/packages/cli/src/util/deploy/get-prebuilt-json.ts
@@ -0,0 +1,12 @@
+import fs from 'fs-extra';
+import { join } from 'path';
+
+export default async function getPrebuiltJson(directory: string) {
+  try {
+    return await fs.readJSON(join(directory, '.vercel/output/builds.json'));
+  } catch (error) {
+    // ignoring error
+  }
+
+  return null;
+}
--- a/packages/cli/src/util/deploy/parse-target.ts
+++ b/packages/cli/src/util/deploy/parse-target.ts
@@ -0,0 +1,41 @@
+import { Output } from '../../util/output';
+import param from '../../util/output/param';
+import code from '../../util/output/code';
+
+/**
+ * Parses the environment target from the `--target` and `--prod` flags.
+ */
+export default function parseTarget(
+  output: Output,
+  targetArg?: string,
+  prodArg?: boolean
+): string | number | undefined {
+  if (targetArg) {
+    const deprecatedTarget = targetArg;
+
+    if (!['staging', 'production'].includes(deprecatedTarget)) {
+      output.error(
+        `The specified ${param('--target')} ${code(
+          deprecatedTarget
+        )} is not valid`
+      );
+      return 1;
+    }
+
+    if (deprecatedTarget === 'production') {
+      output.warn(
+        'We recommend using the much shorter `--prod` option instead of `--target production` (deprecated)'
+      );
+    }
+
+    output.debug(`Setting target to ${deprecatedTarget}`);
+    return deprecatedTarget;
+  }
+
+  if (prodArg) {
+    output.debug('Setting target to production');
+    return 'production';
+  }
+
+  return undefined;
+}
--- a/packages/cli/src/util/deploy/process-deployment.ts
+++ b/packages/cli/src/util/deploy/process-deployment.ts
@@ -9,7 +9,6 @@ import {
 import { Output } from '../output';
 // @ts-ignore
 import Now from '../../util';
-import { VercelConfig } from '../dev/types';
 import { Org } from '../../types';
 import ua from '../ua';
 import { linkFolderToProject } from '../projects/link';
@@ -43,7 +42,6 @@ export default async function processDeployment({
  uploadStamp: () => string;
  deployStamp: () => string;
  quiet: boolean;
-  nowConfig?: VercelConfig;
  force?: boolean;
  withCache?: boolean;
  org: Org;
@@ -62,7 +60,6 @@ export default async function processDeployment({
    deployStamp,
    force,
    withCache,
-    nowConfig,
    quiet,
    prebuilt,
    rootDirectory,
@@ -104,11 +101,7 @@ export default async function processDeployment({
  const indications = [];

  try {
-    for await (const event of createDeployment(
-      clientOptions,
-      requestBody,
-      nowConfig
-    )) {
+    for await (const event of createDeployment(clientOptions, requestBody)) {
      if (['tip', 'notice', 'warning'].includes(event.type)) {
        indications.push(event);
      }
--- a/packages/cli/src/util/env/get-env-records.ts
+++ b/packages/cli/src/util/env/get-env-records.ts
@@ -3,10 +3,20 @@ import Client from '../client';
 import { ProjectEnvVariable, ProjectEnvTarget } from '../../types';
 import { URLSearchParams } from 'url';

+/** The CLI command that was used that needs the environment variables. */
+export type EnvRecordsSource =
+  | 'vercel-cli:env:ls'
+  | 'vercel-cli:env:add'
+  | 'vercel-cli:env:rm'
+  | 'vercel-cli:env:pull'
+  | 'vercel-cli:dev'
+  | 'vercel-cli:pull';
+
 export default async function getEnvRecords(
  output: Output,
  client: Client,
  projectId: string,
+  source: EnvRecordsSource,
  {
    target,
    gitBranch,
@@ -31,6 +41,9 @@ export default async function getEnvRecords(
  if (decrypt) {
    query.set('decrypt', decrypt.toString());
  }
+  if (source) {
+    query.set('source', source);
+  }

  const url = `/v8/projects/${projectId}/env?${query}`;

--- a/packages/cli/src/util/get-decrypted-env-records.ts
+++ b/packages/cli/src/util/get-decrypted-env-records.ts
@@ -6,15 +6,16 @@ import {
  ProjectEnvVariable,
  Secret,
 } from '../types';
-import getEnvRecords from './env/get-env-records';
+import getEnvRecords, { EnvRecordsSource } from './env/get-env-records';

 export default async function getDecryptedEnvRecords(
  output: Output,
  client: Client,
  projectId: string,
+  source: EnvRecordsSource,
  target?: ProjectEnvTarget
 ): Promise<{ envs: ProjectEnvVariable[] }> {
-  const { envs } = await getEnvRecords(output, client, projectId, {
+  const { envs } = await getEnvRecords(output, client, projectId, source, {
    target: target || ProjectEnvTarget.Development,
    decrypt: true,
  });
--- a/packages/cli/src/util/index.ts
+++ b/packages/cli/src/util/index.ts
@@ -160,7 +160,6 @@ export default class Now extends EventEmitter {
      uploadStamp,
      deployStamp,
      quiet,
-      nowConfig,
      force: forceNew,
      withCache,
      org,
--- a/packages/cli/src/util/link/setup-and-link.ts
+++ b/packages/cli/src/util/link/setup-and-link.ts
@@ -6,6 +6,8 @@ import {
  getLinkedProject,
  linkFolderToProject,
  getVercelDirectory,
+  VERCEL_DIR_README,
+  VERCEL_DIR_PROJECT,
 } from '../projects/link';
 import createProject from '../projects/create-project';
 import updateProject from '../projects/update-project';
@@ -49,7 +51,7 @@ export default async function setupAndLink(
  const isFile = !isDirectory(path);
  if (isFile) {
    output.error(`Expected directory but found file: ${path}`);
-    return { status: 'error', exitCode: 1 };
+    return { status: 'error', exitCode: 1, reason: 'PATH_IS_FILE' };
  }
  const link = await getLinkedProject(client, path);
  const isTTY = process.stdout.isTTY;
@@ -65,7 +67,12 @@ export default async function setupAndLink(

  if (forceDelete) {
    const vercelDir = getVercelDirectory(path);
-    remove(vercelDir);
+    remove(join(vercelDir, VERCEL_DIR_README));
+    remove(join(vercelDir, VERCEL_DIR_PROJECT));
+  }
+
+  if (!isTTY && !autoConfirm) {
+    return { status: 'error', exitCode: 1, reason: 'HEADLESS' };
  }

  const shouldStartSetup =
@@ -87,9 +94,14 @@ export default async function setupAndLink(
      autoConfirm
    );
  } catch (err) {
-    if (err.code === 'NOT_AUTHORIZED' || err.code === 'TEAM_DELETED') {
+    if (err.code === 'NOT_AUTHORIZED') {
      output.prettyError(err);
-      return { status: 'error', exitCode: 1 };
+      return { status: 'error', exitCode: 1, reason: 'NOT_AUTHORIZED' };
+    }
+
+    if (err.code === 'TEAM_DELETED') {
+      output.prettyError(err);
+      return { status: 'error', exitCode: 1, reason: 'TEAM_DELETED' };
    }

    throw err;
@@ -135,7 +147,7 @@ export default async function setupAndLink(
    rootDirectory &&
    !(await validateRootDirectory(output, path, sourcePath, ''))
  ) {
-    return { status: 'error', exitCode: 1 };
+    return { status: 'error', exitCode: 1, reason: 'INVALID_ROOT_DIRECTORY' };
  }

  config.currentTeam = org.type === 'team' ? org.id : undefined;
@@ -191,7 +203,11 @@ export default async function setupAndLink(
        if (debug) {
          console.log(deployment);
        }
-        return { status: 'error', exitCode: 1 };
+        return {
+          status: 'error',
+          exitCode: 1,
+          reason: 'MISSING_PROJECT_SETTINGS',
+        };
      }

      const { projectSettings, framework } = deployment;
@@ -227,6 +243,7 @@ export default async function setupAndLink(
    return { status: 'linked', org, project };
  } catch (err) {
    handleError(err);
+
    return { status: 'error', exitCode: 1 };
  }
 }
--- a/packages/cli/src/util/projects/project-settings.ts
+++ b/packages/cli/src/util/projects/project-settings.ts
@@ -1,4 +1,4 @@
-import { writeFile } from 'fs-extra';
+import { outputJSON } from 'fs-extra';
 import { Org, Project, ProjectLink } from '../../types';
 import { getLinkFromDir, VERCEL_DIR, VERCEL_DIR_PROJECT } from './link';
 import { join } from 'path';
@@ -22,21 +22,22 @@ export async function writeProjectSettings(
  project: Project,
  org: Org
 ) {
-  return await writeFile(
-    join(cwd, VERCEL_DIR, VERCEL_DIR_PROJECT),
-    JSON.stringify({
-      projectId: project.id,
-      orgId: org.id,
-      settings: {
-        buildCommand: project.buildCommand,
-        devCommand: project.devCommand,
-        outputDirectory: project.outputDirectory,
-        directoryListing: project.directoryListing,
-        rootDirectory: project.rootDirectory,
-        framework: project.framework,
-      },
-    })
-  );
+  const data = {
+    projectId: project.id,
+    orgId: org.id,
+    settings: {
+      buildCommand: project.buildCommand,
+      devCommand: project.devCommand,
+      outputDirectory: project.outputDirectory,
+      directoryListing: project.directoryListing,
+      rootDirectory: project.rootDirectory,
+      framework: project.framework,
+    },
+  };
+  const path = join(cwd, VERCEL_DIR, VERCEL_DIR_PROJECT);
+  return await outputJSON(path, data, {
+    spaces: 2,
+  });
 }

 export async function readProjectSettings(cwd: string) {
--- a/packages/cli/test/commands/deploy.test.ts
+++ b/packages/cli/test/commands/deploy.test.ts
@@ -2,6 +2,10 @@ import { join } from 'path';
 import { fileNameSymbol } from '@vercel/client';
 import { client } from '../mocks/client';
 import deploy from '../../src/commands/deploy';
+import { setupFixture } from '../helpers/setup-fixture';
+import { defaultProject, useProject } from '../mocks/project';
+import { useTeams } from '../mocks/team';
+import { useUser } from '../mocks/user';

 describe('deploy', () => {
  it('should reject deploying a single file', async () => {
@@ -31,6 +35,59 @@ describe('deploy', () => {
    );
  });

+  it('should reject deploying a directory that does not contain ".vercel/output" when `--prebuilt` is used', async () => {
+    client.setArgv('deploy', __dirname, '--prebuilt');
+    const exitCode = await deploy(client);
+    expect(exitCode).toEqual(1);
+    expect(client.outputBuffer).toEqual(
+      'Error! The "--prebuilt" option was used, but no prebuilt output found in ".vercel/output". Run `vercel build` to generate a local build.\n'
+    );
+  });
+
+  it('should reject deploying a directory that was built with a different target environment when `--prebuilt --prod` is used on "preview" output', async () => {
+    const cwd = setupFixture('build-output-api-preview');
+
+    useUser();
+    useTeams('team_dummy');
+    useProject({
+      ...defaultProject,
+      id: 'build-output-api-preview',
+      name: 'build-output-api-preview',
+    });
+
+    client.setArgv('deploy', cwd, '--prebuilt', '--prod');
+    const exitCode = await deploy(client);
+    expect(exitCode).toEqual(1);
+    expect(client.outputBuffer).toEqual(
+      'Error! The "--prebuilt" option was used with the target environment "production",' +
+        ' but the prebuilt output found in ".vercel/output" was built with target environment "preview".' +
+        ' Please run `vercel --prebuilt`.\n' +
+        'Learn More: https://vercel.link/prebuilt-environment-mismatch\n'
+    );
+  });
+
+  it('should reject deploying a directory that was built with a different target environment when `--prebuilt` is used on "production" output', async () => {
+    const cwd = setupFixture('build-output-api-production');
+
+    useUser();
+    useTeams('team_dummy');
+    useProject({
+      ...defaultProject,
+      id: 'build-output-api-preview',
+      name: 'build-output-api-preview',
+    });
+
+    client.setArgv('deploy', cwd, '--prebuilt');
+    const exitCode = await deploy(client);
+    expect(exitCode).toEqual(1);
+    expect(client.outputBuffer).toEqual(
+      'Error! The "--prebuilt" option was used with the target environment "preview",' +
+        ' but the prebuilt output found in ".vercel/output" was built with target environment "production".' +
+        ' Please run `vercel --prebuilt --prod`.\n' +
+        'Learn More: https://vercel.link/prebuilt-environment-mismatch\n'
+    );
+  });
+
  it('should reject deploying "version: 1"', async () => {
    client.setArgv('deploy');
    client.localConfig = {
--- a/packages/cli/test/commands/env.test.ts
+++ b/packages/cli/test/commands/env.test.ts
@@ -0,0 +1,75 @@
+import fs from 'fs-extra';
+import path from 'path';
+import env from '../../src/commands/env';
+import { setupFixture } from '../helpers/setup-fixture';
+import { client } from '../mocks/client';
+import { defaultProject, useProject } from '../mocks/project';
+import { useTeams } from '../mocks/team';
+import { useUser } from '../mocks/user';
+
+describe('env', () => {
+  describe('pull', () => {
+    it('should handle pulling', async () => {
+      const cwd = setupFixture('vercel-env-pull');
+      useUser();
+      useTeams('team_dummy');
+      useProject({
+        ...defaultProject,
+        id: 'vercel-env-pull',
+        name: 'vercel-env-pull',
+      });
+      client.setArgv('env', 'pull', '--yes', '--cwd', cwd);
+      const exitCode = await env(client);
+      expect(exitCode, client.outputBuffer).toEqual(0);
+
+      const rawDevEnv = await fs.readFile(path.join(cwd, '.env'));
+
+      // check for development env value
+      const devFileHasDevEnv = rawDevEnv.toString().includes('SPECIAL_FLAG');
+      expect(devFileHasDevEnv).toBeTruthy();
+    });
+
+    it('should handle alternate filename', async () => {
+      const cwd = setupFixture('vercel-env-pull');
+      useUser();
+      useTeams('team_dummy');
+      useProject({
+        ...defaultProject,
+        id: 'vercel-env-pull',
+        name: 'vercel-env-pull',
+      });
+      client.setArgv('env', 'pull', 'other.env', '--yes', '--cwd', cwd);
+      const exitCode = await env(client);
+      expect(exitCode, client.outputBuffer).toEqual(0);
+
+      const rawDevEnv = await fs.readFile(path.join(cwd, 'other.env'));
+
+      // check for development env value
+      const devFileHasDevEnv = rawDevEnv.toString().includes('SPECIAL_FLAG');
+      expect(devFileHasDevEnv).toBeTruthy();
+    });
+
+    it('should expose production system env variables', async () => {
+      const cwd = setupFixture('vercel-env-pull');
+      useUser();
+      useTeams('team_dummy');
+      useProject({
+        ...defaultProject,
+        id: 'vercel-env-pull',
+        name: 'vercel-env-pull',
+        autoExposeSystemEnvs: true,
+      });
+
+      client.setArgv('env', 'pull', 'other.env', '--yes', '--cwd', cwd);
+      const exitCode = await env(client);
+      expect(exitCode, client.outputBuffer).toEqual(0);
+
+      const rawDevEnv = await fs.readFile(path.join(cwd, 'other.env'));
+
+      const productionFileHasVercelEnv = rawDevEnv
+        .toString()
+        .includes('VERCEL_ENV="development"');
+      expect(productionFileHasVercelEnv).toBeTruthy();
+    });
+  });
+});
--- a/packages/cli/test/commands/pull.test.ts
+++ b/packages/cli/test/commands/pull.test.ts
@@ -11,15 +11,15 @@ describe('pull', () => {
  it('should handle pulling', async () => {
    const cwd = setupFixture('vercel-pull-next');
    useUser();
-    useTeams();
+    useTeams('team_dummy');
    useProject({
      ...defaultProject,
      id: 'vercel-pull-next',
      name: 'vercel-pull-next',
    });
-    client.setArgv('pull', '--yes', cwd);
+    client.setArgv('pull', cwd);
    const exitCode = await pull(client);
-    expect(exitCode).toEqual(0);
+    expect(exitCode, client.outputBuffer).toEqual(0);

    const rawDevEnv = await fs.readFile(
      path.join(cwd, '.vercel', '.env.development.local')
@@ -28,16 +28,86 @@ describe('pull', () => {
    expect(devFileHasDevEnv).toBeTruthy();
  });

+  it('should fail with message to pull without a link and without --env', async () => {
+    try {
+      process.stdout.isTTY = undefined;
+
+      const cwd = setupFixture('vercel-pull-unlinked');
+      useUser();
+      useTeams('team_dummy');
+
+      client.setArgv('pull', cwd);
+      const exitCode = await pull(client);
+      expect(exitCode, client.outputBuffer).toEqual(1);
+
+      expect(client.outputBuffer).toMatch(
+        /Command `vercel pull` requires confirmation. Use option "--yes" to confirm./gm
+      );
+    } finally {
+      process.stdout.isTTY = true;
+    }
+  });
+
+  it('should fail without message to pull without a link and with --env', async () => {
+    const cwd = setupFixture('vercel-pull-next');
+    useUser();
+    useTeams('team_dummy');
+
+    client.setArgv('pull', cwd, '--yes');
+    const exitCode = await pull(client);
+    expect(exitCode, client.outputBuffer).toEqual(1);
+
+    expect(client.outputBuffer).not.toMatch(
+      /Command `vercel pull` requires confirmation. Use option "--yes" to confirm./gm
+    );
+  });
+
+  it('should handle pulling with env vars (headless mode)', async () => {
+    try {
+      process.env.VERCEL_PROJECT_ID = 'vercel-pull-next';
+      process.env.VERCEL_ORG_ID = 'team_dummy';
+
+      const cwd = setupFixture('vercel-pull-next');
+
+      // Remove the `.vercel` dir to ensure that the `pull`
+      // command creates a new one based on env vars
+      await fs.remove(path.join(cwd, '.vercel'));
+
+      useUser();
+      useTeams('team_dummy');
+      useProject({
+        ...defaultProject,
+        id: 'vercel-pull-next',
+        name: 'vercel-pull-next',
+      });
+      client.setArgv('pull', cwd);
+      const exitCode = await pull(client);
+      expect(exitCode, client.outputBuffer).toEqual(0);
+
+      const config = await fs.readJSON(path.join(cwd, '.vercel/project.json'));
+      expect(config).toMatchInlineSnapshot(`
+        Object {
+          "orgId": "team_dummy",
+          "projectId": "vercel-pull-next",
+          "settings": Object {},
+        }
+      `);
+    } finally {
+      delete process.env.VERCEL_PROJECT_ID;
+      delete process.env.VERCEL_ORG_ID;
+    }
+  });
+
  it('should handle --environment=preview flag', async () => {
    const cwd = setupFixture('vercel-pull-next');
    useUser();
-    useTeams();
+    useTeams('team_dummy');
    useProject({
      ...defaultProject,
      id: 'vercel-pull-next',
      name: 'vercel-pull-next',
    });
-    client.setArgv('pull', '--yes', '--environment=preview', cwd);
+    client.setArgv('pull', '--environment=preview', cwd);
    const exitCode = await pull(client);
    expect(exitCode).toEqual(0);

@@ -53,13 +123,13 @@ describe('pull', () => {
  it('should handle --environment=production flag', async () => {
    const cwd = setupFixture('vercel-pull-next');
    useUser();
-    useTeams();
+    useTeams('team_dummy');
    useProject({
      ...defaultProject,
      id: 'vercel-pull-next',
      name: 'vercel-pull-next',
    });
-    client.setArgv('pull', '--yes', '--environment=production', cwd);
+    client.setArgv('pull', '--environment=production', cwd);
    const exitCode = await pull(client);
    expect(exitCode).toEqual(0);

--- a/packages/cli/test/dev/fixtures/24-ember/.travis.yml
+++ b/packages/cli/test/dev/fixtures/24-ember/.travis.yml
@@ -15,7 +15,7 @@ cache:

 env:
  global:
-    # See https://git.io/vdao3 for details.
+    # See https://github.com/ember-cli/ember-cli/blob/master/docs/build-concurrency.md
    - JOBS=1

 script:
--- a/packages/cli/test/fixtures/unit/build-output-api-preview/.vercel/output/builds.json
+++ b/packages/cli/test/fixtures/unit/build-output-api-preview/.vercel/output/builds.json
@@ -0,0 +1,3 @@
+{
+  "target": "preview"
+}
--- a/packages/cli/test/fixtures/unit/build-output-api-production/.vercel/output/builds.json
+++ b/packages/cli/test/fixtures/unit/build-output-api-production/.vercel/output/builds.json
@@ -0,0 +1,3 @@
+{
+  "target": "production"
+}
--- a/packages/cli/test/fixtures/unit/vercel-env-pull/.gitignore
+++ b/packages/cli/test/fixtures/unit/vercel-env-pull/.gitignore
@@ -0,0 +1,2 @@
+.next
+yarn.lock
--- a/packages/cli/test/fixtures/unit/vercel-env-pull/.vercel/project.json
+++ b/packages/cli/test/fixtures/unit/vercel-env-pull/.vercel/project.json
@@ -0,0 +1,4 @@
+{
+  "orgId": "team_dummy",
+  "projectId": "vercel-env-pull"
+}
--- a/packages/cli/test/fixtures/unit/vercel-env-pull/package.json
+++ b/packages/cli/test/fixtures/unit/vercel-env-pull/package.json
@@ -0,0 +1,12 @@
+{
+  "scripts": {
+    "build": "next build",
+    "dev": "next",
+    "now-build": "next build"
+  },
+  "dependencies": {
+    "next": "^8.0.0",
+    "react": "^16.7.0",
+    "react-dom": "^16.7.0"
+  }
+}
--- a/packages/cli/test/fixtures/unit/vercel-env-pull/pages/index.js
+++ b/packages/cli/test/fixtures/unit/vercel-env-pull/pages/index.js
@@ -0,0 +1,11 @@
+import { withRouter } from 'next/router';
+
+function Index({ router }) {
+  const data = {
+    pathname: router.pathname,
+    query: router.query,
+  };
+  return <div>{JSON.stringify(data)}</div>;
+}
+
+export default withRouter(Index);
--- a/packages/cli/test/fixtures/unit/vercel-env-pull/vercel.json
+++ b/packages/cli/test/fixtures/unit/vercel-env-pull/vercel.json
@@ -0,0 +1,10 @@
+{
+  "version": 2,
+  "name": "vercel-env-pull",
+  "routes": [
+    {
+      "src": "/(.*)",
+      "dest": "/index?route-param=b"
+    }
+  ]
+}
--- a/packages/cli/test/fixtures/unit/vercel-pull-next/.gitignore
+++ b/packages/cli/test/fixtures/unit/vercel-pull-next/.gitignore
@@ -1,3 +1,2 @@
 .next
 yarn.lock
-.vercel
--- a/packages/cli/test/fixtures/unit/vercel-pull-next/.vercel/project.json
+++ b/packages/cli/test/fixtures/unit/vercel-pull-next/.vercel/project.json
@@ -0,0 +1,4 @@
+{
+  "orgId": "team_dummy",
+  "projectId": "vercel-pull-next"
+}
--- a/packages/cli/test/fixtures/unit/vercel-pull-next/vercel.json
+++ b/packages/cli/test/fixtures/unit/vercel-pull-next/vercel.json
@@ -1,7 +1,6 @@
 {
  "version": 2,
  "name": "vercel-pull-next",
-  "builds": [{ "src": "package.json", "use": "@vercel/next@canary" }],
  "routes": [
    {
      "src": "/(.*)",
--- a/packages/cli/test/fixtures/unit/vercel-pull-unlinked/.gitignore
+++ b/packages/cli/test/fixtures/unit/vercel-pull-unlinked/.gitignore
@@ -0,0 +1,2 @@
+.next
+yarn.lock
--- a/packages/cli/test/fixtures/unit/vercel-pull-unlinked/package.json
+++ b/packages/cli/test/fixtures/unit/vercel-pull-unlinked/package.json
@@ -0,0 +1,12 @@
+{
+  "scripts": {
+    "build": "next build",
+    "dev": "next",
+    "now-build": "next build"
+  },
+  "dependencies": {
+    "next": "^8.0.0",
+    "react": "^16.7.0",
+    "react-dom": "^16.7.0"
+  }
+}
--- a/packages/cli/test/fixtures/unit/vercel-pull-unlinked/pages/index.js
+++ b/packages/cli/test/fixtures/unit/vercel-pull-unlinked/pages/index.js
@@ -0,0 +1,11 @@
+import { withRouter } from 'next/router';
+
+function Index({ router }) {
+  const data = {
+    pathname: router.pathname,
+    query: router.query,
+  };
+  return <div>{JSON.stringify(data)}</div>;
+}
+
+export default withRouter(Index);
--- a/packages/cli/test/fixtures/unit/vercel-pull-unlinked/static/robots.txt
+++ b/packages/cli/test/fixtures/unit/vercel-pull-unlinked/static/robots.txt
@@ -0,0 +1 @@
+User-Agent: *
--- a/packages/cli/test/fixtures/unit/vercel-pull-unlinked/vercel.json
+++ b/packages/cli/test/fixtures/unit/vercel-pull-unlinked/vercel.json
@@ -0,0 +1,10 @@
+{
+  "version": 2,
+  "name": "vercel-pull-next",
+  "routes": [
+    {
+      "src": "/(.*)",
+      "dest": "/index?route-param=b"
+    }
+  ]
+}
--- a/packages/cli/test/helpers/prepare.js
+++ b/packages/cli/test/helpers/prepare.js
@@ -179,6 +179,19 @@ module.exports = async function prepare(session, binaryPath) {
      'list/README.md':
        'readme contents for deploy-default-with-conflicting-sub-directory',
    },
+    'deploy-default-with-prebuilt-preview': {
+      'vercel.json': JSON.stringify({ version: 2 }),
+      '.vercel/output/builds.json': JSON.stringify({ target: 'preview' }),
+      '.vercel/output/config.json': JSON.stringify({ version: 3 }),
+      '.vercel/output/static/README.md':
+        'readme contents for deploy-default-with-prebuilt-preview',
+    },
+    'build-output-api-raw': {
+      'vercel.json': JSON.stringify({ version: 2 }),
+      '.vercel/output/config.json': JSON.stringify({ version: 3 }),
+      '.vercel/output/static/README.md':
+        'readme contents for build-output-api-raw',
+    },
    'local-config-v2': {
      [`main-${session}.html`]: '<h1>hello main</h1>',
      [`test-${session}.html`]: '<h1>hello test</h1>',
--- a/packages/cli/test/integration.js
+++ b/packages/cli/test/integration.js
@@ -7,10 +7,9 @@ import { Readable } from 'stream';
 import { homedir } from 'os';
 import _execa from 'execa';
 import XDGAppPaths from 'xdg-app-paths';
-import nodeFetch from 'node-fetch';
+import fetch from 'node-fetch';
 import tmp from 'tmp-promise';
 import retry from 'async-retry';
-import createFetchRetry from '@vercel/fetch-retry';
 import fs, {
  writeFile,
  readFile,
@@ -25,8 +24,6 @@ import pkg from '../package';
 import prepareFixtures from './helpers/prepare';
 import { fetchTokenWithRetry } from '../../../test/lib/deployment/now-deploy';

-const fetch = createFetchRetry(nodeFetch);
-
 // log command when running `execa`
 function execa(file, args, options) {
  console.log(`$ vercel ${args.join(' ')}`);
@@ -497,6 +494,56 @@ test('default command should work with --cwd option', async t => {
  );
 });

+test('should allow deploying a directory that was built with a target environment of "preview" and `--prebuilt` is used without specifying a target', async t => {
+  const projectDir = fixture('deploy-default-with-prebuilt-preview');
+
+  await vcLink(t, projectDir);
+
+  const { exitCode, stderr, stdout } = await execa(
+    binaryPath,
+    [
+      // omit the default "deploy" command
+      '--prebuilt',
+      ...defaultArgs,
+    ],
+    {
+      cwd: projectDir,
+    }
+  );
+
+  t.is(exitCode, 0, formatOutput({ stderr, stdout }));
+
+  const url = stdout;
+  const deploymentResult = await fetch(`${url}/README.md`);
+  const body = await deploymentResult.text();
+  t.deepEqual(body, 'readme contents for deploy-default-with-prebuilt-preview');
+});
+
+test('should allow deploying a directory that was prebuilt, but has no builds.json', async t => {
+  const projectDir = fixture('build-output-api-raw');
+
+  await vcLink(t, projectDir);
+
+  const { exitCode, stderr, stdout } = await execa(
+    binaryPath,
+    [
+      // omit the default "deploy" command
+      '--prebuilt',
+      ...defaultArgs,
+    ],
+    {
+      cwd: projectDir,
+    }
+  );
+
+  t.is(exitCode, 0, formatOutput({ stderr, stdout }));
+
+  const url = stdout;
+  const deploymentResult = await fetch(`${url}/README.md`);
+  const body = await deploymentResult.text();
+  t.deepEqual(body, 'readme contents for build-output-api-raw');
+});
+
 test('deploy using only now.json with `redirects` defined', async t => {
  const target = fixture('redirects-v2');

@@ -796,13 +843,11 @@ test('Deploy `api-env` fixture and test `vercel env` command', async t => {
    t.regex(stderr, /Created .env file/gm);

    const contents = fs.readFileSync(path.join(target, '.env'), 'utf8');
-    t.true(contents.startsWith('# Created by Vercel CLI\n'));
-
-    const lines = new Set(contents.split('\n'));
-    t.true(lines.has('MY_NEW_ENV_VAR="my plaintext value"'));
-    t.true(lines.has('MY_STDIN_VAR="{"expect":"quotes"}"'));
-    t.true(lines.has('MY_DECRYPTABLE_SECRET_ENV="decryptable value"'));
-    t.false(lines.has('MY_PREVIEW'));
+    t.regex(contents, /^# Created by Vercel CLI\n/);
+    t.regex(contents, /MY_NEW_ENV_VAR="my plaintext value"/);
+    t.regex(contents, /MY_STDIN_VAR="{"expect":"quotes"}"/);
+    t.regex(contents, /MY_DECRYPTABLE_SECRET_ENV="decryptable value"/);
+    t.notRegex(contents, /MY_PREVIEW/);
  }

  async function vcEnvPullOverwrite() {
@@ -974,11 +1019,12 @@ test('Deploy `api-env` fixture and test `vercel env` command', async t => {
    const contents = fs.readFileSync(path.join(target, '.env'), 'utf8');

    const lines = new Set(contents.split('\n'));
-    t.true(lines.has('VERCEL="1"'));
-    t.true(lines.has('VERCEL_URL=""'));
-    t.true(lines.has('VERCEL_ENV="development"'));
-    t.true(lines.has('VERCEL_GIT_PROVIDER=""'));
-    t.true(lines.has('VERCEL_GIT_REPO_SLUG=""'));
+
+    t.true(lines.has('VERCEL="1"'), 'VERCEL');
+    t.true(lines.has('VERCEL_URL=""'), 'VERCEL_URL');
+    t.true(lines.has('VERCEL_ENV="development"'), 'VERCEL_ENV');
+    t.true(lines.has('VERCEL_GIT_PROVIDER=""'), 'VERCEL_GIT_PROVIDER');
+    t.true(lines.has('VERCEL_GIT_REPO_SLUG=""'), 'VERCEL_GIT_REPO_SLUG');
  }

  async function vcDevAndFetchSystemVars() {
@@ -1086,29 +1132,48 @@ test('Deploy `api-env` fixture and test `vercel env` command', async t => {
    t.is(exitCode, 0, formatOutput({ stderr, stdout }));
  }

-  await vcLink();
-  await vcEnvLsIsEmpty();
-  await vcEnvAddWithPrompts();
-  await vcEnvAddFromStdin();
-  await vcEnvAddFromStdinPreview();
-  await vcEnvAddFromStdinPreviewWithBranch();
-  await vcEnvLsIncludesVar();
-  await createEnvWithDecryptableSecret();
-  await vcEnvPull();
-  await vcEnvPullOverwrite();
-  await vcEnvPullConfirm();
-  await vcDeployWithVar();
-  await vcDevWithEnv();
-  fs.unlinkSync(path.join(target, '.env'));
-  await vcDevAndFetchCloudVars();
-  await enableAutoExposeSystemEnvs();
-  await vcEnvPullFetchSystemVars();
-  fs.unlinkSync(path.join(target, '.env'));
-  await vcDevAndFetchSystemVars();
-  await vcEnvRemove();
-  await vcEnvRemoveWithArgs();
-  await vcEnvRemoveWithNameOnly();
-  await vcEnvLsIsEmpty();
+  function vcEnvRemoveByName(name) {
+    return execa(binaryPath, ['env', 'rm', name, '-y', ...defaultArgs], {
+      reject: false,
+      cwd: target,
+    });
+  }
+
+  async function vcEnvRemoveAll() {
+    await vcEnvRemoveByName('MY_PREVIEW');
+    await vcEnvRemoveByName('MY_STDIN_VAR');
+    await vcEnvRemoveByName('MY_DECRYPTABLE_SECRET_ENV');
+    await vcEnvRemoveByName('MY_NEW_ENV_VAR');
+  }
+
+  try {
+    await vcEnvRemoveAll();
+    await vcLink();
+    await vcEnvLsIsEmpty();
+    await vcEnvAddWithPrompts();
+    await vcEnvAddFromStdin();
+    await vcEnvAddFromStdinPreview();
+    await vcEnvAddFromStdinPreviewWithBranch();
+    await vcEnvLsIncludesVar();
+    await createEnvWithDecryptableSecret();
+    await vcEnvPull();
+    await vcEnvPullOverwrite();
+    await vcEnvPullConfirm();
+    await vcDeployWithVar();
+    await vcDevWithEnv();
+    fs.unlinkSync(path.join(target, '.env'));
+    await vcDevAndFetchCloudVars();
+    await enableAutoExposeSystemEnvs();
+    await vcEnvPullFetchSystemVars();
+    fs.unlinkSync(path.join(target, '.env'));
+    await vcDevAndFetchSystemVars();
+    await vcEnvRemove();
+    await vcEnvRemoveWithArgs();
+    await vcEnvRemoveWithNameOnly();
+    await vcEnvLsIsEmpty();
+  } finally {
+    await vcEnvRemoveAll();
+  }
 });

 test('[vc projects] should create a project successfully', async t => {
@@ -1446,6 +1511,9 @@ test('try to purchase a domain', async t => {
    {
      reject: false,
      input: stream,
+      env: {
+        FORCE_TTY: '1',
+      },
    }
  );

@@ -2144,11 +2212,6 @@ const verifyExampleAngular = (cwd, dir) =>
  fs.existsSync(path.join(cwd, dir, 'tsconfig.json')) &&
  fs.existsSync(path.join(cwd, dir, 'angular.json'));

-const verifyExampleAmp = (cwd, dir) =>
-  fs.existsSync(path.join(cwd, dir, 'index.html')) &&
-  fs.existsSync(path.join(cwd, dir, 'logo.png')) &&
-  fs.existsSync(path.join(cwd, dir, 'favicon.png'));
-
 test('initialize example "angular"', async t => {
  tmpDir = tmp.dirSync({ unsafeCleanup: true });
  const cwd = tmpDir.name;
@@ -2183,21 +2246,6 @@ test('initialize example ("angular") to specified directory', async t => {
  t.true(verifyExampleAngular(cwd, 'ang'), formatOutput({ stdout, stderr }));
 });

-test('initialize selected example ("amp")', async t => {
-  tmpDir = tmp.dirSync({ unsafeCleanup: true });
-  const cwd = tmpDir.name;
-  const goal = '> Success! Initialized "amp" example in';
-
-  const { stdout, stderr, exitCode } = await execute(['init'], {
-    cwd,
-    input: '\n',
-  });
-
-  t.is(exitCode, 0, formatOutput({ stdout, stderr }));
-  t.true(stderr.includes(goal), formatOutput({ stdout, stderr }));
-  t.true(verifyExampleAmp(cwd, 'amp'), formatOutput({ stdout, stderr }));
-});
-
 test('initialize example to existing directory with "-f"', async t => {
  tmpDir = tmp.dirSync({ unsafeCleanup: true });
  const cwd = tmpDir.name;
@@ -2274,6 +2322,8 @@ test('try to revert a deployment and assign the automatic aliases', async t => {
  const { name } = JSON.parse(
    fs.readFileSync(path.join(firstDeployment, 'now.json'))
  );
+  t.true(!!name, 'name has a value');
+
  const url = `https://${name}.user.vercel.app`;

  {
@@ -2375,6 +2425,9 @@ test('[vercel dev] fails when development commad calls vercel dev recursively',
  const dev = execa(binaryPath, ['dev', ...defaultArgs], {
    cwd: dir,
    reject: false,
+    env: {
+      FORCE_TTY: '1',
+    },
  });

  await setupProject(dev, projectName, {
@@ -2780,6 +2833,9 @@ test('change user', async t => {

  await execute(['login', email, '--api', loginApiUrl, '--debug'], {
    stdio: 'inherit',
+    env: {
+      FORCE_TTY: '1',
+    },
  });

  const auth = await fs.readJSON(getConfigAuthPath());
@@ -2862,7 +2918,7 @@ test('should show prompts to set up project during first deploy', async t => {
  );

  // Send a test request to the deployment
-  const response = await fetch(new URL(output.stdout).href);
+  const response = await fetch(new URL(output.stdout));
  const text = await response.text();
  t.is(text.includes('<h1>custom hello</h1>'), true, text);

@@ -2909,7 +2965,11 @@ test('should prefill "project name" prompt with folder name', async t => {
  const directory = path.join(src, '../', projectName);
  await copy(src, directory);

-  const now = execa(binaryPath, [directory, ...defaultArgs]);
+  const now = execa(binaryPath, [directory, ...defaultArgs], {
+    env: {
+      FORCE_TTY: '1',
+    },
+  });

  await waitForPrompt(now, chunk => /Set up and deploy [^?]+\?/.test(chunk));
  now.stdin.write('yes\n');
@@ -2952,12 +3012,15 @@ test('should prefill "project name" prompt with --name', async t => {
  // remove previously linked project if it exists
  await remove(path.join(directory, '.vercel'));

-  const now = execa(binaryPath, [
-    directory,
-    '--name',
-    projectName,
-    ...defaultArgs,
-  ]);
+  const now = execa(
+    binaryPath,
+    [directory, '--name', projectName, ...defaultArgs],
+    {
+      env: {
+        FORCE_TTY: '1',
+      },
+    }
+  );

  let isDeprecated = false;

@@ -3016,7 +3079,11 @@ test('should prefill "project name" prompt with now.json `name`', async t => {
    })
  );

-  const now = execa(binaryPath, [directory, ...defaultArgs]);
+  const now = execa(binaryPath, [directory, ...defaultArgs], {
+    env: {
+      FORCE_TTY: '1',
+    },
+  });

  let isDeprecated = false;

@@ -3437,7 +3504,12 @@ test('[vc link] should show prompts to set up project', async t => {
  // remove previously linked project if it exists
  await remove(path.join(dir, '.vercel'));

-  const vc = execa(binaryPath, ['link', ...defaultArgs], { cwd: dir });
+  const vc = execa(binaryPath, ['link', ...defaultArgs], {
+    cwd: dir,
+    env: {
+      FORCE_TTY: '1',
+    },
+  });

  await setupProject(vc, projectName, {
    buildCommand: `mkdir -p o && echo '<h1>custom hello</h1>' > o/index.html`,
@@ -3510,7 +3582,13 @@ test('[vc link] should not duplicate paths in .gitignore', async t => {
  const { exitCode, stderr, stdout } = await execa(
    binaryPath,
    ['link', '--confirm', ...defaultArgs],
-    { cwd: dir, reject: false }
+    {
+      cwd: dir,
+      reject: false,
+      env: {
+        FORCE_TTY: '1',
+      },
+    }
  );

  // Ensure the exit code is right
@@ -3536,6 +3614,9 @@ test('[vc dev] should show prompts to set up project', async t => {

  const dev = execa(binaryPath, ['dev', '--listen', port, ...defaultArgs], {
    cwd: dir,
+    env: {
+      FORCE_TTY: '1',
+    },
  });

  await setupProject(dev, projectName, {
@@ -3580,7 +3661,12 @@ test('[vc link] should show project prompts but not framework when `builds` defi
  // remove previously linked project if it exists
  await remove(path.join(dir, '.vercel'));

-  const vc = execa(binaryPath, ['link', ...defaultArgs], { cwd: dir });
+  const vc = execa(binaryPath, ['link', ...defaultArgs], {
+    cwd: dir,
+    env: {
+      FORCE_TTY: '1',
+    },
+  });

  await waitForPrompt(vc, chunk => /Set up [^?]+\?/.test(chunk));
  vc.stdin.write('yes\n');
@@ -3639,6 +3725,9 @@ test('[vc dev] should send the platform proxy request headers to frontend dev se

  const dev = execa(binaryPath, ['dev', '--listen', port, ...defaultArgs], {
    cwd: dir,
+    env: {
+      FORCE_TTY: '1',
+    },
  });

  await setupProject(dev, projectName, {
--- a/packages/cli/test/mocks/client.ts
+++ b/packages/cli/test/mocks/client.ts
@@ -87,7 +87,20 @@ export class MockClient extends Client {
  }

  stopMockServer() {
-    this.mockServer?.close();
+    return new Promise<void>((resolve, reject) => {
+      if (!this.mockServer?.close) {
+        reject(new Error(`mockServer did not exist when closing`));
+        return;
+      }
+
+      this.mockServer.close(error => {
+        if (error) {
+          reject(error);
+          return;
+        }
+        resolve();
+      });
+    });
  }

  setArgv(...argv: string[]) {
@@ -109,6 +122,6 @@ beforeEach(() => {
  client.reset();
 });

-afterAll(() => {
-  client.stopMockServer();
+afterAll(async () => {
+  await client.stopMockServer();
 });
--- a/packages/cli/test/mocks/project.ts
+++ b/packages/cli/test/mocks/project.ts
@@ -1,4 +1,5 @@
 import { client } from './client';
+import { Project } from '../../src/types';

 const envs = [
  {
@@ -36,6 +37,42 @@ const envs = [
  },
 ];

+const systemEnvs = [
+  {
+    type: 'encrypted',
+    id: 'a235l6frtu25df32',
+    key: 'SYSTEM_ENV_FOR_DEV',
+    value: 'development',
+    target: ['development'],
+    gitBranch: null,
+    configurationId: null,
+    updatedAt: 1557241361445,
+    createdAt: 1557241361445,
+  },
+  {
+    type: 'encrypted',
+    id: 'a235l6frtu25df32',
+    key: 'SYSTEM_ENV_FOR_PREV',
+    value: 'preview',
+    target: ['preview'],
+    gitBranch: null,
+    configurationId: null,
+    updatedAt: 1557241361445,
+    createdAt: 1557241361445,
+  },
+  {
+    type: 'encrypted',
+    id: 'a235l6frtu25df32',
+    key: 'SYSTEM_ENV_FOR_PROD',
+    value: 'production',
+    target: ['production'],
+    gitBranch: null,
+    configurationId: null,
+    updatedAt: 1557241361445,
+    createdAt: 1557241361445,
+  },
+];
+
 export const defaultProject = {
  id: 'foo',
  name: 'cli',
@@ -80,25 +117,42 @@ export const defaultProject = {
      requestedAt: 1571239348998,
      target: 'production',
      teamId: null,
-      type: 'LAMBDAS',
+      type: undefined,
      url: 'a-project-name-rjtr4pz3f.vercel.app',
      userId: 'K4amb7K9dAt5R2vBJWF32bmY',
    },
  ],
 };

-export function useProject(project = defaultProject) {
+export function useProject(project: Partial<Project> = defaultProject) {
  client.scenario.get(`/v8/projects/${project.name}`, (_req, res) => {
    res.json(project);
  });
  client.scenario.get(`/v8/projects/${project.id}`, (_req, res) => {
    res.json(project);
  });
+  client.scenario.get(
+    `/v6/projects/${project.id}/system-env-values`,
+    (_req, res) => {
+      const target = _req.query.target || 'development';
+      if (typeof target !== 'string') {
+        throw new Error(
+          `/v6/projects/${project.id}/system-env-values was given a query param of "target=${target}", which is not a valid environment.`
+        );
+      }
+      const targetEnvs = systemEnvs.filter(env => env.target.includes(target));
+
+      res.json({
+        systemEnvValues: targetEnvs,
+      });
+    }
+  );
  client.scenario.get(`/v8/projects/${project.id}/env`, (_req, res) => {
    const target = _req.query.target;
    if (typeof target === 'string') {
      const targetEnvs = envs.filter(env => env.target.includes(target));
      res.json({ envs: targetEnvs });
+      return;
    }

    res.json({ envs });
--- a/Show More
+++ b/Show More