Expo App Doesn't Load on Android

[deshumake]

I created a new repo from this template, followed the quickstart guidelines, and got this error from expo:

Error: Unable to resolve module ./index.ts from C:\Users\...\apps\expo/.: 

None of these files exist:
   * index.ts(.native|.android.ts|.native.ts|.ts|.android.tsx|.native.tsx|.tsx|.android.js|.native.js|.js|.android.jsx|.native.jsx|.jsx|.android.json|.native.json|.json|.android.cjs|.native.cjs|.cjs)
   * index.ts\index(.native|.android.ts|.native.ts|.ts|.android.tsx|.native.tsx|.tsx|.android.js|.native.js|.js|.android.jsx|.native.jsx|.jsx|.android.json|.native.json|.json|.android.cjs|.native.cjs|.cjs)
     at ModuleResolver.resolveDependency (C:\Users\...\node_modules\metro\src\node-haste\DependencyGraph\ModuleResolution.js:153:15)
     at DependencyGraph.resolveDependency (C:\Users\...\node_modules\metro\src\node-haste\DependencyGraph.js:276:43)        
     at C:\Users\...\node_modules\metro\src\lib\transformHelpers.js:171:21
     at Server._resolveRelativePath (C:\Users\...\node_modules\metro\src\Server.js:1256:12)
     at async Server.requestProcessor [as _processBundleRequest] (C:\Users\...\node_modules\metro\src\Server.js:529:37)     
     at async Server._processRequest (C:\Users\...\node_modules\metro\src\Server.js:449:9)

index.ts is definitely in the expo home directory.

What I've tried:

1. Searching up different issues related to "Expo", "Unable to resolve module", and "None of these files exist"
2. Changing the value of "main" in expo's package.json
3. Creating a new t3-turbo repo using a different laptop, and a different phone (Do not have a mac, or iPhone)
4. Creating a brand new expo app using create-expo-app, but then running pnpm install in it.

Results:

• My hunch is that number 4 is the best lead to solving the problem. For this experiment, I made two expo apps using create-expo-app. For one app, I ran npm install (even if it was unnecessary), and in the other, I ran pnpm install. The npm app ran exactly as expected, but the pnpm app gave the exact same error as above (with a different "main" file). I then tried running npm install in the pnpm app; 2 packages were added and 5 packages were changed. I then ran the pnpm expo app again, and it ran like normal.
• There were a bunch of results that seemed to be related to my searching (1), but I don't think any of them were this exact problem. It seemed to be a bunch of actual packages that were missing, and a lot of the solutions to their problems were to fix the way something was imported, or to install a new package.
• Changing the value of "main" (2) would give errors if the path didn't exist. I thought it was possible that the directory it was running from may be different that expected, but after testing a bunch of different paths, it seems like this isn't the case. In normal expo apps, the "main" file is "./node_modules/expo/AppEntry". I tried different variations of this too, but was still either given the error above, or the "path doesn't exist" error
• As for experiment 3, this may be a problem with how I've installed things. I am the common denominator. I did a fresh install of practically everything on new devices though (Android Studio, Expo, setting up env vars, etc.), and at the end of everything, I got the exact same error as given above

Is anyone else able to reproduce this issue? Any ideas about what may be wrong?

[juliusmarminge]

I don't have an android to test with unfortunately.

Anyone else whose able to repro this?

[juliusmarminge]

seems related to #32

[deshumake]

It does look very related to #32.

index.ts\index(.native|.android.ts|.native.ts|.ts|.android.tsx|.native.tsx|.tsx|.android.js|.native.js|.js|.android.jsx|.native.jsx|.jsx|.android.json|.native.json|.json|.android.cjs|.native.cjs|.cjs)

One thing I noticed: if you're currently running pnpm dev, and then add a dot file in the same directory as index.ts, the build progress bar appears for an instant, and another error 'unable to resolve "expo" from index.ts' appears. This error doesn't appear from a fresh run though after adding that file, so this is probably nothing.

Because of this line, I thought that "main" could also take in a folder, so I tried replacing "index.ts" with "src", and moved index.ts into the source folder. It still gives a similar error though.

src\index(.native|.android.ts|.native.ts|.ts|.android.tsx|.native.tsx|.tsx|.android.js|.native.js|.js|.android.jsx|.native.jsx|.jsx|.android.json|.native.json|.json|.android.cjs|.native.cjs|.cjs)

And I feel like this makes less sense than the error before, because the first error seems to be saying that there wasn't an index.ts.ts file, but now it looks like it's actually looking for a normal index.ts file, and that's definitely there in the src dir

[juliusmarminge]

Maybe try downgrading Expo sdk

[deshumake]

Looks like the issue is the version of react and shopify. When I run expo, there is this warning:

Some dependencies are incompatible with the installed expo version:
  @shopify/flash-list@1.4.0 - expected version: 1.3.1
  react@18.2.0 - expected version: 18.1.0
  react-dom@18.2.0 - expected version: 18.1.0
  react-native@0.71.0-rc.0 - expected version: 0.70.5
Your project may not work correctly until you install the correct versions of the packages.
Install individual packages by running npx expo install @shopify/flash-list@1.3.1 react@18.1.0 react-dom@18.1.0 react-native@0.70.5

I assumed that since these versions were in the repo, and no one had issues, that this wouldn't be the problem. After you suggested downgrading, I ran the command in the last line to downgrade these versions, and the app runs now, but more warnings are given:

../..                                    |  WARN  `node_modules` is present. Lockfile only installation will make it out-of-date
 WARN  deprecated uuid@3.4.0: Please upgrade  to version 7 or higher.  Older versions may use Math.random() in certain circumstances, which is known to be problematic.  See https://v8.dev/blog/math-random for details.
 WARN  deprecated @npmcli/move-file@1.1.2: This functionality has been moved to @npmcli/fs
 WARN  deprecated source-map-resolve@0.5.3: See https://github.com/lydell/source-map-resolve#deprecated
 WARN  deprecated resolve-url@0.2.1: https://github.com/lydell/resolve-url#deprecated
 WARN  deprecated source-map-url@0.4.1: See https://github.com/lydell/source-map-url#deprecated
 WARN  deprecated urix@0.1.0: Please see https://github.com/lydell/urix#deprecated                                                                                            
 WARN  deprecated uglify-es@3.3.9: support for ECMAScript is superseded by `uglify-js` as of v3.13.0

Should these warnings just be ignored? Should the versions not actually be downgraded?

[juliusmarminge]

Yes these warnings can be ignored. Everything works as expected with them.

Your issue is not related to these warnings

[deshumake]

Does this versioning not provide any issues for ios?

[cervantes-x]

I am experiencing the same issue. I managed to get Expo Go running again by changing react to version 18.1.0.

As a side effect I'm now unable to create a build. I'm getting the following error message during the gradlew step:

[stderr] FAILURE: Build completed with 2 failures.
[stderr] 1: Task failed with an exception.
[stderr] -----------
[stderr] * Where:
[stderr] Build file '/home/expo/workingdir/build/node_modules/expo/android/build.gradle' line: 9
[stderr] * What went wrong:
[stderr] A problem occurred evaluating project ':expo'.
[stderr] > Cannot invoke method multiply() on null object
[stderr] * Try:
[stderr] > Run with --stacktrace option to get the stack trace.
[stderr] > Run with --info or --debug option to get more log output.
[stderr] > Run with --scan to get full insights.
[stderr] ==============================================================================
[stderr] 2: Task failed with an exception.
[stderr] -----------
[stderr] * Where:
[stderr] Build file '/home/expo/workingdir/build/node_modules/expo/android/build.gradle' line: 79
[stderr] * What went wrong:
[stderr] A problem occurred configuring project ':expo'.
[stderr] > Could not get unknown property 'release' for SoftwareComponentInternal set of type org.gradle.api.internal.component.DefaultSoftwareComponentContainer.
[stderr] * Try:
[stderr] > Run with --stacktrace option to get the stack trace.
[stderr] > Run with --info or --debug option to get more log output.
[stderr] > Run with --scan to get full insights.
[stderr] ==============================================================================
[stderr] * Get more help at https://help.gradle.org
[stderr] BUILD FAILED in 1m 54s
Error: Gradle build failed with unknown error. See logs for the "Run gradlew" phase for more information.

I'm not sure why but when I change all the react versions in the monorepo to use 18.1.0 the builds start to work again. I feel like there is something wrong with the configuration not fetching the packages from the correct location.

[jimboboliver]

Running npx expo-cli doctor --fix-dependencies in the expo app directory fixes this for me, but I have only tested the expo app with Android.

[juliusmarminge]

Running npx expo-cli doctor --fix-dependencies in the expo app directory fixes this for me, but I have only tested the expo app with Android.

I hope Expo SDK 48 isn't too far out so that we can use React 18.2 with full support - although I haven't noticed it not working as it is now.

[juliusmarminge]

Closing as completed. I'll leave the React 18.2 in there for now as it seems to work for most (you are the first one who have reported an issue related to this).

If someone else comes across this in the future, try the solution above and downgrade to the officially supported versions - Expo SDK 48 should introduce official support for these which will let us suppress these warnings for good!

[deshumake]

Sounds good. Thanks for the help!

[pencilcheck]

The command has been updated to npx expo-doctor And running this in the expo somehow fixed it for me when trying to run on Android emulator, even though the command said there is nothing wrong with the repo. lol