Fails to build with XCode 10 beta command line tools.

error is: `AttributeError: 'NoneType' object has no attribute 'groups'`

This may very well be an issue that is related to the command line tools, so fine to close it. But I wanted to report this in case people run into the same issue.

For me the solution was to uninstall XCode Command Line Tools and then re-install them for Xcode 9.4 from https://developer.apple.com/download/more/