[expo-51] Android app unable to resolve module expo-router/entry inside monorepo (new arch enabled or not)

[sync]

Minimal reproducible example

https://github.com/sync/borg

What platform(s) does this occur on?

Android

Did you reproduce this issue in a development build?

Yes

Summary

When I run the app on Android in development mode I get the following error as soon as I add to the metro config monorepo support as per your documentation. The same app if not run inside a monotrepo work just fine. And the exact same config on iOS is fine.

/Users/xxx/Projects/expo/borg-mono/node_modules/metro/src/node-haste/DependencyGraph/ModuleResolution.js:112
        throw new UnableToResolveError(
              ^
Error: Unable to resolve module ./node_modules/expo-router/entry from /Users/xxx/Projects/expo/borg-mono/apps/borg/.: 

None of these files exist:
  * node_modules/expo-router/entry(.android.ts|.native.ts|.ts|.android.tsx|.native.tsx|.tsx|.android.mjs|.native.mjs|.mjs|.android.js|.native.js|.js|.android.jsx|.native.jsx|.jsx|.android.json|.native.json|.json|.android.cjs|.native.cjs|.cjs|.android.scss|.native.scss|.scss|.android.sass|.native.sass|.sass|.android.css|.native.css|.css)
  * node_modules/expo-router/entry/index(.android.ts|.native.ts|.ts|.android.tsx|.native.tsx|.tsx|.android.mjs|.native.mjs|.mjs|.android.js|.native.js|.js|.android.jsx|.native.jsx|.jsx|.android.json|.native.json|.json|.android.cjs|.native.cjs|.cjs|.android.scss|.native.scss|.scss|.android.sass|.native.sass|.sass|.android.css|.native.css|.css)
    at ModuleResolver.resolveDependency (/Users/xxx/Projects/expo/borg-mono/node_modules/metro/src/node-haste/DependencyGraph/ModuleResolution.js:112:15)
    at DependencyGraph.resolveDependency (/Users/xxx/Projects/expo/borg-mono/node_modules/metro/src/node-haste/DependencyGraph.js:231:43)
    at /Users/xxx/Projects/expo/borg-mono/node_modules/metro/src/lib/transformHelpers.js:156:21
    at HmrServer._registerEntryPoint (/Users/xxx/Projects/expo/borg-mono/node_modules/metro/src/HmrServer.js:49:35)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async Promise.all (index 0)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
error Command failed.
Exit code: 1
Command: /Users/xxx/Library/Application Support/fnm/node-versions/v18.19.1/installation/bin/node
Arguments: /Users/xxx/Library/Application Support/fnm/node-versions/v18.19.1/installation/lib/node_modules/yarn/lib/cli.js android
Directory: /Users/xxx/Projects/expo/borg-mono/apps/borg
Output:

iOS

works perfectly

Environment

expo-env-info 1.2.0 environment info:
System:
OS: macOS 14.4.1
Shell: 5.9 - /bin/zsh
Binaries:
Node: 18.19.1 - ~/Library/Caches/fnm_multishells/6402_1715493990830/bin/node
Yarn: 1.22.22 - ~/Library/Caches/fnm_multishells/6402_1715493990830/bin/yarn
npm: 10.2.4 - ~/Library/Caches/fnm_multishells/6402_1715493990830/bin/npm
Watchman: 2024.05.06.00 - /opt/homebrew/bin/watchman
Managers:
CocoaPods: 1.15.2 - /Users/anthonymittaz/.gem/ruby/2.7.4/bin/pod
SDKs:
iOS SDK:
Platforms: DriverKit 23.4, iOS 17.4, macOS 14.4, tvOS 17.4, visionOS 1.1, watchOS 10.4
IDEs:
Android Studio: 2023.2 AI-232.10300.40.2321.11567975
Xcode: 15.3/15E204a - /usr/bin/xcodebuild
npmGlobalPackages:
eas-cli: 9.0.2
Expo Workflow: bare

Expo Doctor Diagnostics

✔ Check Expo config for common issues
✔ Check package.json for common issues
✔ Check dependencies for packages that should not be installed directly
✔ Check for issues with metro config
✔ Check for common project setup issues
✔ Check npm/ yarn versions
✔ Check Expo config (app.json/ app.config.js) schema
✔ Check native tooling versions
✔ Check for legacy global CLI installed locally
✔ Check that native modules do not use incompatible support packages
✔ Check that packages match versions required by installed Expo SDK
✔ Check that native modules use compatible support package versions for installed Expo SDK

Didn't find any issues with the project!

[sync]

EXPO_USE_METRO_WORKSPACE_ROOT=1 in a .env or before the start command fixes it, I guess it is required ?

[byCedric]

Hi @sync! Thanks for reporting this issue. Monorepos are hard, and the resolving logic in Metro isn't helping here at all. Eventhough I can't seem to reproduce this exact issue in your repository, one way this might be fixed (besides the EXPO_USE_METRO_WORKSPACE_ROOT=1) is this:

• Create your own entryfile, e.g. apps/borg/index.ts
• Only add import 'expo-router/entry'; in this entry file
• Change apps/borg/package.json main to index.ts.

This is because Metro might not play nice with a combination of entry points from node_modules and monorepos. I do the exact same thing in my monorepo example here.

Hope this helps!