Fail to build using Xcode 12 Beta 4

[igoriols]

Description

When I try to build a project with Xcode 12 Beta 4 to test iOS14, I got a plenty of Undefined symbols for architecture x86_64. Every time I build the app, the list of errors is changed. Native libraries fail to recognize base React classes.

React Native version:

info Fetching system and libraries information...
(node:16978) Warning: Accessing non-existent property 'padLevels' of module exports inside circular dependency
(Use `node --trace-warnings ...` to show where the warning was created)
System:
    OS: macOS 10.15.6
    CPU: (12) x64 Intel(R) Core(TM) i7-8750H CPU @ 2.20GHz
    Memory: 558.54 MB / 16.00 GB
    Shell: 5.7.1 - /bin/zsh
  Binaries:
    Node: 14.3.0 - /usr/local/bin/node
    Yarn: 1.22.4 - /usr/local/bin/yarn
    npm: 6.14.4 - /usr/local/bin/npm
    Watchman: 4.9.0 - /usr/local/bin/watchman
  Managers:
    CocoaPods: 1.9.3 - /Users/laigorols/.rbenv/shims/pod
  SDKs:
    iOS SDK:
      Platforms: iOS 14.0, DriverKit 20.0, macOS 11.0, tvOS 14.0, watchOS 7.0
    Android SDK: Not Found
  IDEs:
    Android Studio: 4.0 AI-193.6911.18.40.6626763
    Xcode: 12.0/12A8179i - /usr/bin/xcodebuild
  Languages:
    Java: 12.0.1 - /usr/bin/javac
    Python: 2.7.16 - /Users/laigorols/.pyenv/shims/python
  npmPackages:
    @react-native-community/cli: Not Found
    react: 16.13.1 => 16.13.1
    react-native: 0.63.2 => 0.63.2
  npmGlobalPackages:
    *react-native*: Not Found

Steps To Reproduce

Provide a detailed list of steps that reproduce the issue.

1. Add native dependencies to package.json;
2. Install dependencies using yarn install;
3. Run pod install in ios folder to auto link native dependencies;
4. Try to run application in simulator using Xcode;

Expected Results

Application is successfully installed and executed in simulator.

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

Xcode error log:
Build Xcode12ReactNativeSample_2020-08-12T17-06-23.txt

Github repository with sample: https://github.com/igoriols/xcode12reactnativesample

[naveen-c]

+1 facing the same issue Undefined symbols for architecture x86_64

[xiao99xiao]

+1 here. Only fails with Xcode 12 beta with Debug, while Release works. Xcode 11.6 works.
Derived data is cleaned every time.

Workaround: use Legacy Build System in Xcode.
But be noticed that platforms dependency selection and SwiftUI Preview will be unavailable with legacy build system.

[igoriols]

Hi @xiao99xiao, thank you for the workaround. Unfortunately, I can't use this in my real project. Another errors arise if I change to the legacy build system. Besides that, legacy build system is deprecated and is scheduled to be removed in a future Xcode release.

I think there is something missing in build settings, but I can't figure out what it is yet. Maybe we need to set a new configuration for the iOS's scripts.

Any help to solve this problem is appreciated.

[xiao99xiao]

Update: issue still exists with Xcode 12 Beta 5. Also, upgrading Cocoapods to 1.10 beta doesn't help.

The issue seems to be related with React Native's Auto-linking. So building a React Native only project won't be affected, but if you bring in some libraries like react-native-safe-area or react-native-webview , the compiling fails.

After comparing the affected targets with other React Native targets, I found that React.framework was missing in the Link Binary With Libraries build phase for those auto-linked pods.

So I came up with a Workaround:
Add a post_install in Podfile to manually add the React.framework back. (Update: Please notice that I used :generate_multiple_pod_projects => true in my Podfile.)

post_install do |installer|
  #Workaround for Xcode 12 and Auto-Linking
  installer.pod_target_subprojects.each do |project|
    project.targets.each do |target|
      if ['react-native-netinfo', 'react-native-randombytes'].include?(target.name) #list all affected target in the array
        target.build_phases.each do |build_phases|
          if build_phases.display_name == 'Frameworks'
            file_ref = project.new(Xcodeproj::Project::Object::PBXFileReference)
            file_ref.path = 'React.framework'
            file_ref.source_tree = 'BUILT_PRODUCTS_DIR'
            build_phases.add_file_reference(file_ref)
          end
        end        
      end
    end
  end
end

Still, hope this could be fixed on React Native side.

[igoriols]

Hi @xiao99xiao , thanks for your help. Just let me see if I understand it right: this script adds React.framework to Link Binary With Libraries build phase for each native library pods (the ones Auto-linked) that uses react-native. Is that right?

I used the following script:

post_install do |installer|
  #Workaround for Xcode 12 and Auto-Linking
  installer.pod_target_subprojects.each do |project|
    project.targets.each do |target|
      if ['RNCAsyncStorage', 'RNGestureHandler', 'RNPermissions', 'RNReanimated', 'RNScreens', 'RNShare', 'react-native-netinfo', 'react-native-safe-area-context', 'react-native-webview', 'rn-fetch-blob'].include?(target.name) #list all affected target in the array
        target.build_phases.each do |build_phases|
          if build_phases.display_name == 'Frameworks'
            file_ref = project.new(Xcodeproj::Project::Object::PBXFileReference)
            file_ref.path = 'React.framework'
            file_ref.source_tree = 'BUILT_PRODUCTS_DIR'
            build_phases.add_file_reference(file_ref)
          end
        end        
      end
    end
  end
end

The Undefined symbols for architecture x86_64 errors persists and the script didn't add React.framework in Link Binary With Libraries. Did I do something wrong when I used your script?

I don't know if it means something for the issue, but there was a React (pods) in Dependencies section already. I thought the libs were importing react's dependencies this way:

[naveen-c]

@xiao99xiao thanks for the workaround, it's compiling for me now.

@igoriols you might need to update the script a bit as per your use case.

Pasting the script that worked for me:

  #Workaround for Xcode 12 and Auto-Linking
  installer.pods_project.targets.each do |target|
    if ['react-native-netinfo', 'react-native-shimmer', 'react-native-webview'].include?(target.name) #list all affected target in the array
      target.build_phases.each do |build_phases|
        if build_phases.display_name == 'Frameworks'
          file_ref = installer.pods_project.new(Xcodeproj::Project::Object::PBXFileReference)
          file_ref.path = 'React.framework'
          file_ref.source_tree = 'BUILT_PRODUCTS_DIR'
          build_phases.add_file_reference(file_ref)
        end
      end
    end
  end

[xiao99xiao]

@igoriols Sorry, I forgot to mention that I used :generate_multiple_pod_projects => true in my Podfile.
Therefore my pod project structure is different from yours.
You could either
add install! 'cocoapods', :disable_input_output_paths => true, :generate_multiple_pod_projects => true to your Podfile and try again,
or
rewrite the code to adapt to your pod target structure. To be more specificly, the part below

installer.pod_target_subprojects.flat_map { |p| p.targets }.each do |target|
    target.build_configurations.each do |config|

should be replaced by

installer.pods_project.targets.each do |target|

[chrisglein]

Sounds like there's a workaround available for now (other than not using the beta). Anyone here know what the fix would actually be to that native iOS implementation to address this on the inside? At some point beta not going to be beta anymore and this will need to be fixed.

[xiao99xiao]

I think the easy way is to modify the https://github.com/react-native-community/cli/blob/master/packages/platform-ios/native_modules.rb file, to add the React.framework link dependency to each pod. However I have little knowledge about ruby, hope someone else could have a look at it.

The hard way is to dive deep and see why Xcode 12 requires a React.framework linking while Xcode 11 doesn't, which I don't have a clue yet.

[sudeepdino008]

+1 having the same issue.

[igoriols]

Thanks to @xiao99xiao and @naveen-c , I was able to use the following script to solve my problem with the workaround:

post_install do |installer|
  installer.pods_project.targets.each do |target|
    #Workaround for Xcode 12 and Auto-Linking
    if ['RNCAsyncStorage', 'RNGestureHandler', 'RNReanimated', 'RNScreens', 'RNShare', 'react-native-webview', 'react-native-safe-area-context', 'react-native-netinfo'].include?(target.name) #list all affected target in the array
      target.build_phases.each do |build_phases|
        if build_phases.display_name == 'Frameworks'
          file_ref = installer.pods_project.new(Xcodeproj::Project::Object::PBXFileReference)
          file_ref.path = 'React.framework'
          file_ref.source_tree = 'BUILT_PRODUCTS_DIR'
          build_phases.add_file_reference(file_ref)
        end
      end
    end
    if ['react-native-safe-area-context'].include?(target.name)
      target.build_phases.each do |build_phases|
        if build_phases.display_name == 'Frameworks'
          file_ref = installer.pods_project.new(Xcodeproj::Project::Object::PBXFileReference)
          file_ref.path = 'yoga.framework'
          file_ref.source_tree = 'BUILT_PRODUCTS_DIR'
          build_phases.add_file_reference(file_ref)
        end
      end
    end
  end
end

I had to add yoga.framework to react-native-safe-area-context, also. 😕