Build passing for upstream repo, failing for identical fork

The build for hamcrest/PyHamcrest is passing, as I think it should. A build for my fork of this repo, brunns/PyHamcrest, fails, ERROR: InterpreterNotFound: python3.4. The failing build seems to be picking up a newer point release of Python, but I can’t see any other reason for the failure. Is this a bug, or have I configured something incorrectly?

That explains it, yes, thanks.