Fixing file 'project.pch' has been modified since the precompiled header was built error in Xcode
You could try a deep clean (not the same as Product > Clean) - Option+Command+Shift+K
Note: this means the clean the build folder (by pressing Option + Product -> clean folder)
- Close your project or workspace.
- In Finder: ⇧shift+⌘cmd+G
- Paste:
~/Library/Developer/Xcode/DerivedData/ - Delete the
ModuleCachefolder and empty trash. - Open up your project.
- Clean: ⇧shift+⌘cmd+K
- Build: ⌘cmd+B
In my case the error message had a small hint:
note: after modifying system headers, please delete the module cache at '~/Library/Developer/Xcode/DerivedData/ModuleCache/5CYAJ91AZCB7'
I tried and it worked.