Get error "You must set MODELDIR environment variable" from CLI call to predictoor/main.py

[trentmc]

To reproduce: do predictoor setup like in its README. Up to doing this CLI call:

python pdr_backend/predictoor/main.py

What this call should have done is give guidance on using approach 1 or 2.

Instead, it raised an error: "You must set MODELDIR environment variable". That's an approach2 specific thing.

Also: the CLI should give better hints about what to do, depending what you give it.

[trizin]

The issue arises when executing python pdr_backend/predictoor/main.py because it imports approach2/main.py. In approach2/main.py, there's a call to getenv_or_exit("MODELDIR") directly within the file scope and not inside a function. Hence, when the file is imported, the environment check is triggered immediately, leading to that error.

074c0e9 looks like a nice fix!

[trentmc]

Yep, I know.

I've fixed it in this PR, will merge soon.
#100

I also cleaned up the CLI a bit in general