[0.79.3] Multiple commands produce - Fabric

[radekzz]

Description

After upgrading to RN 0.79.3 i started having this failing iOS build:

error Multiple commands produce '/Users/radek/Library/Developer/Xcode/DerivedData/MyApp-busjatodvgaqfkaofsfubqrkrqmx/Build/node_modules/react-native/ReactCommon/react/renderer/consistency/ShadowTreeRevisionConsistencyManager.h'
error Multiple commands produce '<Copy /Users/radek/Library/Developer/Xcode/DerivedData/MyApp-busjatodvgaqfkaofsfubqrkrqmx/Build/node_modules/react-native/ReactCommon/react/renderer/consistency/ShadowTreeRevisionConsistencyManager.h>'

I found tons of threads about same error title, but always with different files or libraries.

What i tried:

• Remove DerivedData
• Reinstall pods
• Move use_frameworks! :linkage => :static above use_react_native()
• Checked that i don't have any duplicates in Target -> Build Phases -> Copy Bundle Resources

I also tried to remove duplicate files in post_install like:

      if target.name == 'React-FabricComponents'
        target.headers_build_phase.files.each do |file|
          if file.display_name.include?('RCTComponentViewHelpers.h') ||
             file.display_name.include?('ScrollView')
            file.remove_from_project
          end
        end
      end
    end

Android builds, so the issue i have is only this one with iOS.

Steps to reproduce

1. install RN 0.79.3
2. install pods
3. run ios

React Native Version

0.79.3

Affected Platforms

Build - MacOS

Output of npx @react-native-community/cli info

System:
  OS: macOS 14.6.1
  CPU: (10) arm64 Apple M1 Pro
  Memory: 288.67 MB / 16.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 20.19.0
    path: ~/.nvm/versions/node/v20.19.0/bin/node
  Yarn:
    version: 1.22.19
    path: /opt/homebrew/bin/yarn
  npm:
    version: 10.8.2
    path: ~/.nvm/versions/node/v20.19.0/bin/npm
  Watchman:
    version: 2025.07.28.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.16.2
    path: /usr/local/bin/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 24.2
      - iOS 18.2
      - macOS 15.2
      - tvOS 18.2
      - visionOS 2.2
      - watchOS 11.2
  Android SDK: Not Found
IDEs:
  Android Studio: 2025.1 AI-251.25410.109.2511.13752376
  Xcode:
    version: 16.2/16C5032a
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.10
    path: /usr/bin/javac
  Ruby:
    version: 2.6.10
    path: /usr/bin/ruby
npmPackages:
  "@react-native-community/cli": Not Found
  react:
    installed: 19.0.0
    wanted: "*"
  react-native:
    installed: 0.79.3
    wanted: "*"
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: true
  newArchEnabled: false

Stacktrace or Logs

error Multiple commands produce '/Users/radek/Library/Developer/Xcode/DerivedData/MyApp-busjatodvgaqfkaofsfubqrkrqmx/Build/node_modules/react-native/ReactCommon/react/renderer/consistency/ShadowTreeRevisionConsistencyManager.h'
error Multiple commands produce '<Copy /Users/radek/Library/Developer/Xcode/DerivedData/MyApp-busjatodvgaqfkaofsfubqrkrqmx/Build/node_modules/react-native/ReactCommon/react/renderer/consistency/ShadowTreeRevisionConsistencyManager.h>'

MANDATORY Reproducer

none

Screenshots and Videos

No response

[react-native-bot]

Warning

Missing reproducer: We could not detect a reproducible example in your issue report. Reproducers are mandatory and we can accept only one of those as a valid reproducer:

• For majority of bugs: send us a Pull Request with the RNTesterPlayground.js edited to reproduce your bug.
• If your bug is UI related: a Snack
• If your bug is build/upgrade related: a project using our Reproducer Template

You can read more about about it on our website: How to report a bug.

[atulgpt17]

Hi @radekzz can you add valid repro using the template https://github.com/react-native-community/reproducer-react-native/generate ?

[radekzz]

Solved.

I was using NX monorepo and it was making duplicates in mobile folder.

[atulgpt17]

Hi @radekzz thanks for the update. I am closing this issue as Invalid

[react-native-bot]

Caution

Invalid issue: This issue is not valid, either is not a bug in React Native, it doesn't match any of the issue template, or we can't help further with this.