App force close on release mode: undefined is not an object (evaluating 'e.length')

Is this a bug report?

Yes

Have you read the Contributing Guidelines?

Yes

Environment

Environment: OS: macOS High Sierra 10.13 Node: 8.9.0 Yarn: 1.2.1 npm: 5.5.1 Watchman: 4.7.0 Xcode: Xcode 9.1 Build version 9B37 Android Studio: 3.0 AI-171.4402976

Packages: (wanted => installed) react: ^16.0.0 => 16.0.0 react-native: ^0.50.2 => 0.50.2

Target Platform: iOS (11.1)

Steps to Reproduce

1. App with React Native v0.50+ installed
2. Run debug build (works)
3. Run release build (crash on app open)

Expected Behavior

Not crash

Actual Behavior

Crash on app open with this error: RCTFatalException: Unhandled JS Exception: undefined is not an object (evaluating 'e.length')'

Stack points inside the color-converter package.

Current workaround

• Downgrade to 0.49.5

[mobdim]

My solution:

"react-native": "0.50.3",
"react": "^16.0.0",

remove resolutions from package.json

and build steps:

watchman watch-del-all
rm -rf $TMPDIR/react-*
rm yarn.lock
rm android/app/src/main/assets/index.android.bundle
rm android/app/src/main/assets/index.android.bundle.meta
yarn cache clean
yarn install
mkdir -p android/app/src/main/assets/
react-native bundle --platform android --dev false --entry-file index.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res/
cd android
./gradlew clean
./gradlew assembleDebug
cd ..

Everything ok!

[andrew-wagner89]

I was able to fix the problem by resolving the color-convert package to use the pull request here: Qix-/color-convert/pull/49

just changed my package.json to include: "resolutions": { "color-convert": "github:zbarbuto/color-convert" }

this is just a workaround though since other packages might declare the same var twice which breaks uglify