添加watchOS target后出现No such module 'FirebaseFirestore'问题求助

Key Issues #

• FirebaseFirestore (and FirebaseFirestoreSwift) does not support watchOS (confirmed in your error for version 10.3.0).
• Shared files used by both iOS and watchOS targets are attempting to import FirebaseFirestore, which is unavailable in the watchOS build context.
• Your Podfile applies identical Firebase pods to both targets, but watchOS can't handle Firestore or its dependent libraries.

Step-by-Step Fixes #

1. Split Firebase Pods by Platform #

Modify your Podfile to separate Firebase pods into iOS-only and watchOS-only groups, since not all Firebase libraries support watchOS:

def ios_firebase_pods
  pod 'Firebase/Database'
  pod 'Firebase/Auth'
  pod 'Firebase/Storage'
  pod 'Firebase/RemoteConfig'
  pod 'Firebase/Firestore' # Re-enable only if your iOS target needs it
  # pod 'FirebaseFirestoreSwift' # Only include here (iOS-only) if required
end

def watchos_firebase_pods
  pod 'Firebase/Auth' # Supported on watchOS
  pod 'Firebase/RemoteConfig' # Supported on watchOS
  # Exclude Database, Storage, Firestore—these don't work on watchOS
end

Update your target definitions to use the correct pod groups:

target 'HonestMate' do
  platform :ios, '16.0'
  use_frameworks!

  helpers_pods
  ios_firebase_pods

  target 'HonestMateTests' do
    inherit! :search_paths
  end

  target 'HonestMateUITests' do
  end
end

target 'HonestMate Watch App' do
  platform :watchos, '9.0'
  use_frameworks!

  watchos_firebase_pods
end

2. Guard Firestore Code for iOS Only #

In any shared files that import FirebaseFirestore, wrap the relevant code with platform conditionals to prevent compilation for watchOS:

#if os(iOS)
import FirebaseFirestore
// All Firestore-specific logic goes here
#endif

Alternatively, if entire files are Firestore-exclusive, remove them from the watchOS target's membership:

1. Select the file in the Project Navigator
2. Open the File Inspector (right sidebar)
3. Uncheck the watchOS target under Target Membership

3. Fix Post-Install Script #

Your current script sets the iOS deployment target for all targets, including watchOS. Update it to target only iOS platforms:

post_install do |installer|
  installer.pods_project.targets.each do |target|
    target.build_configurations.each do |config|
      if target.platform.name == :ios
        config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '16.0'
      end
      if target.platform.name == :watchos
        config.build_settings['WATCHOS_DEPLOYMENT_TARGET'] = '9.0'
      end
    end
  end
end

4. Reinstall Pods #

Run these commands to clean and refresh your Pod setup:

pod deintegrate
pod install

5. Handling FirebaseFirestoreSwift #

Since it depends on Firestore (unsupported on watchOS), you can only include it in the iOS target. Uncomment it in ios_firebase_pods and ensure any code using it is wrapped in #if os(iOS) guards.

Verification #

• Open the .xcworkspace file (never use .xcodeproj with CocoaPods).
• Clean the build folder (Cmd+Opt+K) and delete Derived Data (Xcode > Settings > Locations > Derived Data > Delete).
• Build both iOS and watchOS targets separately to confirm no module errors.

内容的提问来源于stack exchange，提问作者Karina