Class is implemented in both, One of the two will be used. Which one is undefined

Question

I have an issue with dependencies included in Cocoapods.

I have a Framework project (MyFramework target), which also has App target (MyFrameworkExampleApp). When I try to run the app, I get a console full of errors like so:

Class PodsDummy_AFNetworking is implemented in both /private/var/containers/Bundle/Application/AD85D7EC-2652-4019-94FB-C799D0FBA69B/MyFrameworkExampleApp.app/Frameworks/MyFramework.framework/MyFramework (0x1019a0438) and /var/containers/Bundle/Application/AD85D7EC-2652-4019-94FB-C799D0FBA69B/MyFrameworkExampleApp.app/MyFrameworkExampleApp (0x10107c558). One of the two will be used. Which one is undefined.

The thing is, the errors come from the libraries included only in MyFramework target

Here are the contents of my podfile:

# Specify platform.
platform :ios, '9.0'

# Let's ignore all warnings from all pods
inhibit_all_warnings!

target 'MyFramework’ do

    # ReactiveCocoa for easier binding between UI and data models.
    pod 'ReactiveCocoa', '< 3.0'

    # ReactiveViewModel for easier handling of active/inactive view models.
    pod 'ReactiveViewModel', '0.3'

    # An Objective-C extension with some nice helpers including @weakify/@strongify.
    pod 'libextobjc', '~> 0.4.1'

    # AFNetworking Security stuff
    pod 'AFNetworking/Security', '~> 2.5.4'

    # KZPropertyMapper to easily map JSON dicts to properties
    pod "KZPropertyMapper"

    # Simple wrapper for KeyChain
    pod 'UICKeyChainStore', '~> 2.0.6'

    # Animated gifs
    pod 'FLAnimatedImage', '~> 1.0'

    # Firebase push notifications
    pod 'Firebase/Core'
    pod 'Firebase/Messaging'

    # Easy image downloading with cache.
    pod 'SDWebImage', '~> 3.7.2'

    # Activity indicator for RBSlider
    pod 'DGActivityIndicatorView'

end

target 'MyFrameworkExampleApp' do

    # Progress indicator
    pod 'MBProgressHUD', '~> 1.0.0'

    # Color picker
    pod 'iOS-Color-Picker'

    # Hockey SDK
    pod 'HockeySDK', '~> 5.0.0'

end

As you can see, App target does not inherit any pods, nor do I have any global pods. What might be the reason for this?

Answer 1

I also found another a script someone wrote that fix the bug automatically. It's simply make the same I answered above. Add it to your Podfile:

post_install do |installer|
    sharedLibrary = installer.aggregate_targets.find { |aggregate_target| aggregate_target.name == 'Pods-[MY_FRAMEWORK_TARGET]' }
    installer.aggregate_targets.each do |aggregate_target|
        if aggregate_target.name == 'Pods-[MY_APP_TARGET]'
            aggregate_target.xcconfigs.each do |config_name, config_file|
                sharedLibraryPodTargets = sharedLibrary.pod_targets
                aggregate_target.pod_targets.select { |pod_target| sharedLibraryPodTargets.include?(pod_target) }.each do |pod_target|
                    pod_target.specs.each do |spec|
                        frameworkPaths = unless spec.attributes_hash['ios'].nil? then spec.attributes_hash['ios']['vendored_frameworks'] else spec.attributes_hash['vendored_frameworks'] end || Set.new
                        frameworkNames = Array(frameworkPaths).map(&:to_s).map do |filename|
                            extension = File.extname filename
                            File.basename filename, extension
                        end
                    end
                    frameworkNames.each do |name|
                        if name != '[DUPLICATED_FRAMEWORK_1]' && name != '[DUPLICATED_FRAMEWORK_2]'
                            raise("Script is trying to remove unwanted flags: #{name}. Check it out!")
                        end
                        puts "Removing #{name} from OTHER_LDFLAGS"
                        config_file.frameworks.delete(name)
                    end
                end
            end
            xcconfig_path = aggregate_target.xcconfig_path(config_name)
            config_file.save_as(xcconfig_path)
        end
    end
end

Answer 2

https://github.com/CocoaPods/CocoaPods/issues/7126#issuecomment-399395611

post_install do |installer|
    applicationTargets = [
        'Pods-SampleApp',
    ]
    libraryTargets = [
        'Pods-SampleLib',
    ]

    embedded_targets = installer.aggregate_targets.select { |aggregate_target|
        libraryTargets.include? aggregate_target.name
    }
    embedded_pod_targets = embedded_targets.flat_map { |embedded_target| embedded_target.pod_targets }
    host_targets = installer.aggregate_targets.select { |aggregate_target|
        applicationTargets.include? aggregate_target.name
    }

    # We only want to remove pods from Application targets, not libraries
    host_targets.each do |host_target|
        host_target.xcconfigs.each do |config_name, config_file|
            host_target.pod_targets.each do |pod_target|
                if embedded_pod_targets.include? pod_target
                    pod_target.specs.each do |spec|
                        if spec.attributes_hash['ios'] != nil
                            frameworkPaths = spec.attributes_hash['ios']['vendored_frameworks']
                            else
                            frameworkPaths = spec.attributes_hash['vendored_frameworks']
                        end
                        if frameworkPaths != nil
                            frameworkNames = Array(frameworkPaths).map(&:to_s).map do |filename|
                                extension = File.extname filename
                                File.basename filename, extension
                            end
                            frameworkNames.each do |name|
                                puts "Removing #{name} from OTHER_LDFLAGS of target #{host_target.name}"
                                config_file.frameworks.delete(name)
                            end
                        end
                    end
                end
            end
            xcconfig_path = host_target.xcconfig_path(config_name)
            config_file.save_as(xcconfig_path)
        end
    end
end

Answer 3

Updated: I write a blog article for my solution: https://medium.com/@GalvinLi/tinysolution-fix-cocoapods-duplicate-implement-warning-5a2e1a505ea8

And a demo project: https://github.com/bestwnh/TinySolution

---

I got the solution idea from internet but can't find one solution work, so I make a workaround by myself. Maybe the code is a bit long, but it work. Hope it can help someone.

The auto_process_target(,,) is the key function, just change it to fit your project and all should work fine. (Because I use one framework for multi app target, so I make the app target parameter be an array.)

post_install do |installer|

  # you should change the sample auto_process_target method call to fit your project

  # sample for the question
  auto_process_target(['MyFrameworkExampleApp'], 'MyFramework', installer)
  # sample for the multi app use on same framework
  auto_process_target(['exampleiOSApp', 'exampleMacApp'], 'exampleFramework', installer)

end

# the below code no need to modify

def auto_process_target(app_target_names, embedded_target_name, installer)
  words = find_words_at_embedded_target('Pods-' + embedded_target_name,
                                        installer)
  handle_app_targets(app_target_names.map{ |str| 'Pods-' + str },
                     words,
                     installer)
end

def find_line_with_start(str, start)
  str.each_line do |line|
      if line.start_with?(start)
        return line
      end
  end
  return nil
end

def remove_words(str, words)
  new_str = str
  words.each do |word| 
    new_str = new_str.sub(word, '')
  end
  return new_str
end

def find_words_at_embedded_target(target_name, installer)
  target = installer.pods_project.targets.find { |target| target.name == target_name }
  target.build_configurations.each do |config|
    xcconfig_path = config.base_configuration_reference.real_path
    xcconfig = File.read(xcconfig_path)
    old_line = find_line_with_start(xcconfig, "OTHER_LDFLAGS")

    if old_line == nil 
      next
    end
    words = old_line.split(' ').select{ |str| str.start_with?("-l") }.map{ |str| ' ' + str }
    return words
  end
end

def handle_app_targets(names, words, installer)
  installer.pods_project.targets.each do |target|
    if names.index(target.name) == nil
      next
    end
    puts "Updating #{target.name} OTHER_LDFLAGS"
    target.build_configurations.each do |config|
      xcconfig_path = config.base_configuration_reference.real_path
      xcconfig = File.read(xcconfig_path)
      old_line = find_line_with_start(xcconfig, "OTHER_LDFLAGS")

      if old_line == nil 
        next
      end
      new_line = remove_words(old_line, words)

      new_xcconfig = xcconfig.sub(old_line, new_line)
      File.open(xcconfig_path, "w") { |file| file << new_xcconfig }
    end
  end
end

If all work. You will see Update xxxx OTHER_LDFLAGS when you pod install or pod update. Then the warning gone.