Intermittent problem when analysing complex workspaces with Swift development CocoaPods
Looks like this may be a bug in xcodebuild when handling Swift pods: https://github.com/CocoaPods/CocoaPods/issues/3555
May also be the problem we had with tests, just due to the very complex nature of CocoaPods dependencies in this project.
/Users/dcutting/Library/Developer/Xcode/DerivedData/Rocket-dvbrmgjcdanzbhapdjbpdxmfgcln/Build/Intermediates.noindex/Pods.build/Debug-iphoneos/LoadablePodResource.build/unextended-module.modulemap:2:19: error: umbrella header 'LoadablePodResource-umbrella.h' not found umbrella header "LoadablePodResource-umbrella.h" ^ <unknown>:0: error: could not build Objective-C module 'LoadablePodResource'
https://stackoverflow.com/questions/32381933/invalid-virtual-filesystem-overlay-file
Since it's intermittent and fails at different times with different modules, it is probably related to something cached in DerivedData or similar. Clearing this between building each module may help, but possibly slow things down even more.