Ahh, I did miss that bit, but it doesn't really matter.

Tell modwsgi to only use the main interpreter ("PythonInterpreter
main_interpreter"), and if you want multiple modules of the same name
put them in different packages.  Any other problems (trac using env vars
for configuration) should be fixed directly.

(My previous comment about building your own import mechanism was
overkill.  Writing a package that uses relative imports is enough - in
fact, that's what relative imports are for.)