C compiler cannot create executables (installing Cocoapods)
Set your XCODE CLI via XCode preferences and then run pod install again.
Xcode -> Preferences -> Locations -> Command Line Tools
Open Xcode
- Select Xcode goto Preferences...
- Select Loctions and set Command Line Tools
For me running sudo xcode-select --reset fixed it.
Prior I also installed/updated gcc with brew upgrade gcc, not sure if this a prerequisite.