Fix Flipper-Folly on iOS 14.5

Podfile

target 'YourAPP' do

  config = use_native_modules!

  use_react_native!(:path => config["reactNativePath"])

  target 'YourAPP' do
    inherit! :complete
    # Pods for testing
  end

  # Enables Flipper.
  #
  # Note that if you have use_frameworks! enabled, Flipper will not work and
  # you should disable these next few lines.
  use_flipper!({ 'Flipper-Folly' => '2.3.0' })            # <=== Step 1
  post_install do |installer|
    flipper_post_install(installer)

    ## Fix for Flipper-Folly on iOS 14.5                    <=== Step 2
  find_and_replace("Pods/Flipper-Folly/folly/synchronization/DistributedMutex-inl.h",
  "atomic_notify_one(state)", "folly::atomic_notify_one(state)")

  find_and_replace("Pods/Flipper-Folly/folly/synchronization/DistributedMutex-inl.h",
  "atomic_wait_until(&state, previous | data, deadline)", "folly::atomic_wait_until(&state, previous | data, deadline)")
  end

  ## Fix for Flipper-Folly on iOS 14.5                     <=== Step 3
  def find_and_replace(dir, findstr, replacestr)
    Dir[dir].each do |name|
        text = File.read(name)
        replace = text.gsub(findstr,replacestr)
        if text != replace
            puts "Fix: " + name
            File.open(name, "w") { |file| file.puts replace }
            STDOUT.flush
        end
    end
    Dir[dir + '*/'].each(&method(:find_and_replace))
  end
end

After you Added the 3 Steps:

• Remove Pods folder
• Remove Podfile.lock
• npx pod-install

Found here:

• https://stackoverflow.com/questions/66019068/event2-event-config-h-file-not-found
• https://stackoverflow.com/questions/67290697/react-native-0-64-wont-build-ios-app-after-updating-xcode-to-12-5-and-ios-to-14