packages with pth-files can't be build

[woodfighter]

When trying to build coloredlogs, I encountered the error

Expected to find a single 'dist-packages' directory inside converted package!

when building with --install-prefix=/usr/local. The second dist-package py2deb encounters contains the pth-file of coloredlogs and AFAIK it's correct that it should point to a different directory (here /usr/local/lib/python3/dist-packages/ instead of /usr/local/lib/python3.5/dist-packages/coloredlogs).