[iOS] 'mainjs.bundle.map' not found when composing sourcemaps with Hermes.

Description

When building the app for iOS, if you set the env var SOURCEMAP_FILE when bundling it generates an error when composing sourcemaps.

As I understand the culprit appears to be this parts of the react-native-xcode.sh script:

If SOURCEMAP_FILE is not empty, then EMIT_SOURCEMAP.

EMIT_SOURCEMAP=
if [[ ! -z “$SOURCEMAP_FILE” ]]; then
  EMIT_SOURCEMAP=true
fi

Here it seems that if EMIT_SOURCEMAP is true, it generates the sourcemap in the bundle script

PACKAGER_SOURCEMAP_FILE=
if [[ $EMIT_SOURCEMAP == true ]]; then
  if [[ $USE_HERMES == true ]]; then
    PACKAGER_SOURCEMAP_FILE=“$CONFIGURATION_BUILD_DIR/$(basename $SOURCEMAP_FILE)”
  else
    PACKAGER_SOURCEMAP_FILE=“$SOURCEMAP_FILE”
  fi
  EXTRA_ARGS=“$EXTRA_ARGS --sourcemap-output $PACKAGER_SOURCEMAP_FILE”
fi

if [[ $USE_HERMES != true ]]; then
  cp “$BUNDLE_FILE” “$DEST/”
  BUNDLE_FILE=“$DEST/main.jsbundle”
else
  EXTRA_COMPILER_ARGS=
  if [[ $DEV == true ]]; then
    EXTRA_COMPILER_ARGS=-Og
  else
    EXTRA_COMPILER_ARGS=-O
  fi

Here it where confuses me, I don’t know (and couldn’t find them) which flags and how they work for the Hermes compiler. Here the flag “-output-source-map” is setted but I don’t actually know if it does something.

  if [[ $EMIT_SOURCEMAP == true ]]; then
    EXTRA_COMPILER_ARGS=“$EXTRA_COMPILER_ARGS -output-source-map”
  fi
  “$HERMES_CLI_PATH” -emit-binary $EXTRA_COMPILER_ARGS -out “$DEST/main.jsbundle” “$BUNDLE_FILE”

And here is kind of weird too. It seems that a “mainjs.bundle.map” should exist next to “main.jsbundle” but it doesn’t, hence causing the error.

if [[ $EMIT_SOURCEMAP == true ]]; then
    HBC_SOURCEMAP_FILE=“$BUNDLE_FILE.map”
    “$NODE_BINARY” “$COMPOSE_SOURCEMAP_PATH” “$PACKAGER_SOURCEMAP_FILE” “$HBC_SOURCEMAP_FILE” -o “$SOURCEMAP_FILE”
  fi
  BUNDLE_FILE=“$DEST/main.jsbundle”
fi

This is the build phase:

export NODE_BINARY=node
export SOURCEMAP_FILE=“${PROJECT_DIR}/../sourcemap.ios.js”
export PROJECT_ROOT=“${PROJECT_DIR}/../”
../../../node_modules/react-native/scripts/react-native-xcode.sh index.js

This is the XCode report: bundle-xcode-report.txt

The error is:

+ [[ true == true ]]
+ HBC_SOURCEMAP_FILE=/Users/path/to/DerivedData/intermediates/BuildProductsPath/Release.development-iphoneos/main.jsbundle.map
+ node /Users/user/Workspace/UtilityGO-Office-Mobile/node_modules/react-native/scripts/compose-source-maps.js /Users/path/to/DerivedData/intermediates/BuildProductsPath/Release.development-iphoneos/sourcemap.ios.js /Users/path/to/DerivedData/intermediates/BuildProductsPath/Release.development-iphoneos/main.jsbundle.map -o /Users/path/to/ios/workspace/../sourcemap.ios.js
internal/fs/utils.js:314
    throw err;
    ^

Error: ENOENT: no such file or directory, open '/Users/path/to/DerivedData/intermediates/BuildProductsPath/Release.development-iphoneos/main.jsbundle.map'
    at Object.openSync (fs.js:498:3)
    at Object.readFileSync (fs.js:394:35)
    at Object.<anonymous> (/Users/user/Workspace/UtilityGO-Office-Mobile/node_modules/react-native/scripts/compose-source-maps.js:35:8)
    at Module._compile (internal/modules/cjs/loader.js:1085:14)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1114:10)
    at Module.load (internal/modules/cjs/loader.js:950:32)
    at Function.Module._load (internal/modules/cjs/loader.js:790:14)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:76:12)
    at internal/main/run_main_module.js:17:47 {
  errno: -2,
  syscall: 'open',
  code: 'ENOENT',
  path: '/Users/path/to/DerivedData/intermediates/BuildProductsPath/Release.development-iphoneos/main.jsbundle.map'
}

I don’t know if I’m misunderstanding how SOURCEMAP_FILE works, if doing something wrong or is actually a bug.

It would be really great if I can get some help with this!

Thank you!

Version

0.65.1

Output of react-native info

System: OS: macOS 11.6 CPU: (4) x64 Intel® Core™ i5-5257U CPU @ 2.70GHz Memory: 1.15 GB / 8.00 GB Shell: 5.8 - /bin/zsh Binaries: Node: 14.17.3 - /var/folders/16/pt1bzhnj0t723m8dhdfjv8c80000gn/T/yarn–1635445381302-0.42400434651762153/node Yarn: 1.22.10 - /var/folders/16/pt1bzhnj0t723m8dhdfjv8c80000gn/T/yarn–1635445381302-0.42400434651762153/yarn npm: 7.24.0 - ~/Workspace/UtilityGO-Office-Mobile/node_modules/.bin/npm Watchman: 2021.06.07.00 - /usr/local/bin/watchman Managers: CocoaPods: 1.10.2 - /usr/local/bin/pod SDKs: iOS SDK: Platforms: iOS 14.5, DriverKit 20.4, macOS 11.3, tvOS 14.5, watchOS 7.4 Android SDK: Not Found IDEs: Android Studio: 2020.3 AI-203.7717.56.2031.7583922 Xcode: 12.5.1/12E507 - /usr/bin/xcodebuild Languages: Java: javac 17 - /usr/bin/javac npmPackages: @react-native-community/cli: Not Found react: Not Found react-native: Not Found react-native-macos: Not Found npmGlobalPackages: react-native: Not Found

Steps to reproduce

Add SOURCEMAP_FILE env var when bundling, like this:

export NODE_BINARY=node
export SOURCEMAP_FILE=“${PROJECT_DIR}/../sourcemap.ios.js”
export PROJECT_ROOT=“${PROJECT_DIR}/../”
../../../node_modules/react-native/scripts/react-native-xcode.sh index.js

Snack, code example, screenshot, or link to a repository

No response

[kidroca]

I’ve stumbled on that bug too - specifying a SOURCEMAP_FILE path in xCode’s build phase would fail if you have hermes enabled, because of a filename mismatch

It’s because of this part here: https://github.com/facebook/react-native/blob/4ea38e16bf533955557057656cba5346d2372acd/scripts/react-native-xcode.sh#L169-L174

Since we set -out "$DEST/main.jsbundle" the (hbc) source maps would be output next to main.jsbundle in $DEST

The line here needs to change

HBC_SOURCEMAP_FILE="$BUNDLE_FILE.map" 

$BUNDLE_FILE refers to the packager bundle file, which is still outside of $DEST hence the error

Error: ENOENT: no such file or directory, open ‘/Users/path/to/DerivedData/intermediates/BuildProductsPath/Release.development-iphoneos/main.jsbundle.map’

The HBC_SOURCEMAP_FILE is inside $DEST

Suggested change:

- HBC_SOURCEMAP_FILE="$BUNDLE_FILE.map"
+ HBC_SOURCEMAP_FILE="$DEST/main.jsbundle.map" 

[taltrui]

Hi! Does anyone knows something about this?

Thanks!