Source: pygalmesh Followup-For: Bug #946233 Good that you found why cmake is mislaunching for you. It's a strange bug. Behaviour like that should never depend on the order in which files got written to disk. Please do file a bug against dh-python.
I don't want to insert Build-Conflicts: cmake into the package since that will interfere with other build tests (I don't want to have to uninstall cmake just to test a local build of pygalmesh). But we can leave this bug open to report it as a workaround for systems which are affected by the problem. When you file the bug against dh-python, please tag it as blocking this bug.