Yes, I'm on Linux also(Mint). I had guessed that the Python versions might be to blame so in the build commands I had put in 'python3 -m py_ompile "%f"' hoping that would direct the process away from the older python 2.7, but it didn't help. Didn't hurt though. I also thought about the path, but wasn't sure how to check that, not that familiar yet with Linux directory structure, but using your path, found mine is the same, and sure enough where you have 'FT_00_CM=python3 -m py_compile "%f"', I had the same line with python instead of python3. With Supervisor privileges I renamed the filenames.python file to oldfilenames.python, edited a copy of it to make the change to an entry for python3 and replaced the original file. Nothing was broken, but it still acts the same way. Frustrating and puzzling.
Are there any other simple IDE's out there for python? I'd be willing to try another one. Geany is certainly appealing, but if I can't import modules, it's not going to be very useful. It still acts like its seeing the lower python version, but I don't know where else that could be coming from.