Something is trying to use the devDependency 'metro-config' when building a production release build

[Voxar]

Environment

info Fetching system and libraries information... (node:11799) [DEP0040] DeprecationWarning: The punycode module is deprecated. Please use a userland alternative instead. (Use node --trace-deprecation ... to show where the warning was created) System: OS: macOS 14.3.1 CPU: (8) arm64 Apple M1 Pro Memory: 327.63 MB / 32.00 GB Shell: version: 3.6.1 path: /opt/homebrew/bin/fish Binaries: Node: version: 21.7.3 path: /opt/homebrew/bin/node Yarn: version: 1.22.22 path: /opt/homebrew/bin/yarn npm: version: 10.5.2 path: /opt/homebrew/bin/npm Watchman: version: 2024.04.15.00 path: /opt/homebrew/bin/watchman Managers: CocoaPods: version: 1.15.2 path: /opt/homebrew/bin/pod SDKs: iOS SDK: Platforms: - DriverKit 23.2 - iOS 17.2 - macOS 14.2 - tvOS 17.2 - visionOS 1.0 - watchOS 10.2 Android SDK: Not Found IDEs: Android Studio: 2021.2 AI-212.5712.43.2112.8815526 Xcode: version: 15.2/15C500b path: /usr/bin/xcodebuild Languages: Java: version: 11.0.16.1 path: /Library/Java/JavaVirtualMachines/microsoft-11.jdk/Contents/Home/bin/javac Ruby: version: 3.3.0 path: /opt/homebrew/bin/ruby npmPackages: "@react-native-community/cli": Not Found react: Not Found react-native: Not Found react-native-macos: Not Found npmGlobalPackages: "react-native": Not Found Android: hermesEnabled: true newArchEnabled: false iOS: hermesEnabled: true newArchEnabled: false

Description

Something is trying to use the devDependency 'metro-config' when building a production release build. I did not find relevant open issues.

+ /opt/homebrew/bin/node /Users/voxar/projects/AwesomeProject/node_modules/react-native/cli.js bundle --entry-file index.js --platform ios --dev false --reset-cache --bundle-output /Users/voxar/Library/Developer/Xcode/DerivedData/AwesomeProject-aohpaqzpsscvpicbmnzrzycupwsx/Build/Products/Release-iphoneos/main.jsbundle --assets-dest /Users/voxar/Library/Developer/Xcode/DerivedData/AwesomeProject-aohpaqzpsscvpicbmnzrzycupwsx/Build/Products/Release-iphoneos/AwesomeProject.app --minify false
(node:18816) [DEP0040] DeprecationWarning: The `punycode` module is deprecated. Please use a userland alternative instead.
(Use `node --trace-deprecation ...` to show where the warning was created)
error Cannot find module '@react-native/metro-config'
Require stack:
- /Users/voxar/projects/AwesomeProject/metro.config.js
- /Users/voxar/projects/AwesomeProject/node_modules/cosmiconfig/node_modules/import-fresh/index.js
- /Users/voxar/projects/AwesomeProject/node_modules/cosmiconfig/dist/loaders.js
- /Users/voxar/projects/AwesomeProject/node_modules/cosmiconfig/dist/createExplorer.js
- /Users/voxar/projects/AwesomeProject/node_modules/cosmiconfig/dist/index.js
- /Users/voxar/projects/AwesomeProject/node_modules/@react-native-community/cli-config/build/readConfigFromDisk.js
- /Users/voxar/projects/AwesomeProject/node_modules/@react-native-community/cli-config/build/loadConfig.js
- /Users/voxar/projects/AwesomeProject/node_modules/@react-native-community/cli-config/build/index.js
- /Users/voxar/projects/AwesomeProject/node_modules/@react-native-community/cli/build/commands/index.js
- /Users/voxar/projects/AwesomeProject/node_modules/@react-native-community/cli/build/index.js
- /Users/voxar/projects/AwesomeProject/node_modules/react-native/cli.js.
Error: Cannot find module '@react-native/metro-config'
Require stack:
- /Users/voxar/projects/AwesomeProject/metro.config.js
- /Users/voxar/projects/AwesomeProject/node_modules/cosmiconfig/node_modules/import-fresh/index.js
- /Users/voxar/projects/AwesomeProject/node_modules/cosmiconfig/dist/loaders.js
- /Users/voxar/projects/AwesomeProject/node_modules/cosmiconfig/dist/createExplorer.js
- /Users/voxar/projects/AwesomeProject/node_modules/cosmiconfig/dist/index.js
- /Users/voxar/projects/AwesomeProject/node_modules/@react-native-community/cli-config/build/readConfigFromDisk.js
- /Users/voxar/projects/AwesomeProject/node_modules/@react-native-community/cli-config/build/loadConfig.js
- /Users/voxar/projects/AwesomeProject/node_modules/@react-native-community/cli-config/build/index.js
- /Users/voxar/projects/AwesomeProject/node_modules/@react-native-community/cli/build/commands/index.js
- /Users/voxar/projects/AwesomeProject/node_modules/@react-native-community/cli/build/index.js
- /Users/voxar/projects/AwesomeProject/node_modules/react-native/cli.js
    at Module._resolveFilename (node:internal/modules/cjs/loader:1142:15)
    at Module._load (node:internal/modules/cjs/loader:983:27)
    at Module.require (node:internal/modules/cjs/loader:1230:19)
    at require (node:internal/modules/helpers:179:18)
    at Object.<anonymous> (/Users/voxar/projects/AwesomeProject/metro.config.js:1:41)
    at Module._compile (node:internal/modules/cjs/loader:1368:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1426:10)
    at Module.load (node:internal/modules/cjs/loader:1205:32)
    at Module._load (node:internal/modules/cjs/loader:1021:12)
    at Module.require (node:internal/modules/cjs/loader:1230:19)

Reproducible Demo

npx react-native@latest init AwesomeProject
cd AwesomeProject
yarn --production
cd ios
bundle
bundle exec pod install

• Open project in Xcode
• Edit scheme and switch Build Configuration to "Release"
• Build

[szymonrybczak]

May I ask why do you pass --production flag to when installing packages? Without passing this flag, everything works correctly.

[Voxar]

@szymonrybczak without it you also get the devDependencies which you would not want to include in a production build.

[robhogan]

1. You'll need the dev dependencies to build. Build tools (like Metro) themselves are typically dev dependencies.
2. That's fine, because Metro will only bundle files in use by your project (it crawls import and require from your entry point) - it doesn't just bundle everything.

[Voxar]

Oh, I thought Metro was just a dev server.

So there's not really any point in separating packages betwen "dependencies" and "devDepencendies" then, other than semantics?

What is NODE_ENV=production / yarn --production for?