问题
I keep getting this error along with "'FirebaseCore/FirebaseCore.h' file not found". I've reinstalled my pods about 4 times. Cleaning my project works for about 5 seconds the the first error pops up again then when I try to build it I get the second error. I've been researching for three days, I've tried every suggestion I've seen, and none of them have worked. Is anyone else having the same problem? Please help.
回答1:
The current Firebase 5.x requires at least CocoaPods version 1.4.0. Add your Podfile contents to the question if you're still having problems after upgrading CocoaPods.
来源：https://stackoverflow.com/questions/51025067/could-not-build-objective-c-module-firebase-i-have-xcode-version-9-4-1-coco