GIDSignInButton is blank

It turned out that Pods were not initiated properly and Targets->Project->Build Phases->Copy Pods Resources was missing. Deleting Pods directory didn't help.

The solution was:

sudo gem install cocoapods-deintegrate
pod deintegrate
pod install

That's old enough question, I know. But I've met the issue. In case if someone is too, my GIDSignInButton View was blank because under Custom Class the Module was set to "Inherit Module From Target", it shouldn't and Module should be None.

Other options didn't help.