Test error with new versioning

[frostedoyster]

Running the tests locally with python -m pytest errors due to the fact that _version is not present (I believe pytest tests from the metatrain folder and not its installation, which would instead contain the module)
@PicoCentauri
@Luthaf

[PicoCentauri]

Hmmm, this is weird. If you haven't installed the package pytest should use (an old) installed version of your enviroment, which should not have the _version.py. And once you installed it the file should be present.

May I ask why are you using pytest directly and not via tox in an isolated environment?

[frostedoyster]

I like using pytest directly because it's much faster (no new environment to create) and because it gives me control over the environment that I'm running the tests in

I don't know if it's expected, but, as long as I was installing with --no-build-isolation --no-deps or --no-build-isolation I was getting the missing _version errors, but then I installed once without the flags and everything is working well. I have no clue what's going on

[PicoCentauri]

I assume when you use these flags the build process is not triggered fully and setuptools-scm is not triggered to create the version file.

I thinl there is not mhuch we can do. Basically these extra options are dangerous and you have to know what you are doing 😝

[frostedoyster]

I see that a _version.py was created in my directory (and git wants to commit it, we should probably add it to gitignore)

[PicoCentauri]

It is...

[Luthaf]

I don't know if it's expected, but, as long as I was installing with --no-build-isolation --no-deps or --no-build-isolation I was getting the missing _version errors, but then I installed once without the flags and everything is working well. I have no clue what's going on

You really should not need --no-build-isolation for this project, since the point of the flag for us is to (a) prevent installing torch & co in a separate virtualenv and (b) build against an already installed torch version. Since metatrain does not depend on torch at build time, this does nothing.

[Luthaf]

Overall, I think this is not an officially supported workflow, only tox is. If tox is too slow for you we can try to make it faster, but it should not re-create environments after the first time.

[frostedoyster]

--no-build-isolation was for the soap-bpnn extra dependency
I tried to install again with --no-build-isolation and it didn't work. The first time that you install without the flag, then it starts working. IMO, in general, we should support --no-build-isolation so that more optimized and customized versions can be used on HPC platforms

[Luthaf]

We don't need --no-build-isolation for metatrain itself. If someone wants to play with this, I would suggest installing the dependencies manually with --no-build-isolation, and then pip install metatrain --no-deps