Xcode 10.1
After trying other suggestions found here #8091 (comment) and at Incorrect path for Pods.debug.xcconfig in Xcode?
I found that Kaspik’s suggestion worked:
pod deintegrate
pod install
edit the .xcodeproj/project.pbxproj file and change the PBXGroup “path = Pods” to “name = Pods”
source https://github.com/CocoaPods/CocoaPods/issues/8091
updated from: pod reintegrate to: pod deintegrate