Fixing "/ios/Pods/FirebaseAuth/Firebase/Auth/Source/FIRAuth.m:25:9: 'FirebaseAuthInterop/FIRAuthInterop.h' file not found"

Today the build suddenly failed for iOS (but not Android), with this cryptic error message.

It turns out Cocoapods also broke because of the Mac OS update from last month. So I had to reinstall it the same way I did for Fastlane at my previous post:

sudo gem install cocoapods -n /usr/local/bin

This installs Cocoapods into /usr/local. So I wonder if sudo is necessary in that case. Maybe not.

Then running flutter build ios --release --no-codesign still failed with another cryptic message:

firebase_auth (from .symlinks/plugins/firebase_auth/ios) was resolved to 0.0.1, which depends on Firebase/Auth (~> 6.0) was resolved to 6.0.0, which depends on...

Eventually I ended up on this post that suggests two things:

  • Update Firebase dependencies.
  • Run an update with Cocoapod.

The second suggestion fixed it:

my_project/ios $ pod update