plumed: add libtorch and metatomic support

[RMeli]

No description provided.

[RMeli]

@spackbot fix style

[spackbot-app]

Let me see if I can fix that for you!

[spackbot-app]

I was able to run spack style --fix for you!

spack style --fix

repos/spack_repo/builtin/packages/dd4hep/package.py
repos/spack_repo/builtin/packages/graphviz/package.py
repos/spack_repo/builtin/packages/mapl/package.py
repos/spack_repo/builtin/packages/petaca/package.py
repos/spack_repo/builtin/packages/plumed/package.py
repos/spack_repo/builtin/packages/podio/package.py
repos/spack_repo/builtin/packages/py_cartopy/package.py
repos/spack_repo/builtin/packages/py_pygobject/package.py
repos/spack_repo/builtin/packages/py_torch/package.py
repos/spack_repo/builtin/packages/seacas/package.py
repos/spack_repo/builtin/packages/truchas/package.py
�[1;34m==> �[0mrunning flake8
repos/spack_repo/builtin/packages/plumed/package.py:273: [W293] blank line contains whitespace
repos/spack_repo/builtin/packages/plumed/package.py:286: [E501] line too long (106 > 99 characters)
repos/spack_repo/builtin/packages/plumed/package.py:304: [E741] ambiguous variable name 'l'
repos/spack_repo/builtin/packages/plumed/package.py:335: [E303] too many blank lines (2)
repos/spack_repo/builtin/packages/py_torch/package.py:809: [E501] line too long (110 > 99 characters)
�[1;34m==> �[0mrunning isort
Fixing /tmp/tmpvornvl89/fork/repos/spack_repo/builtin/packages/plumed/package.py
�[1;34m==> �[0mrunning black

Keep in mind that I cannot fix your flake8 or mypy errors, so if you have any you'll need to fix them and update the pull request. If I was able to push to your branch, if you make further changes you will need to pull from your updated branch before pushing again.

I've updated the branch with style fixes.

[Luthaf]

is there a way to automatically enable pytorch when the user request metatomic, and only error if the user explicitly disable pytorch?

[RMeli]

This is what this conflicts does. It allows +pytorch ~metatomic (which is valid, as far as I understand), but disallows ~pytorch +metatomic. If you select only +metatomic then the pytorch variant automatically needs to be +pytorch if not specified in order to satisfy the constraint. However, if a user explicitly requires +metatomic ~pytorch, then an error is triggered.

This is essentially because the conflicts is stronger than the variant default value, see https://spack.readthedocs.io/en/latest/frequently_asked_questions.html#why-does-spack-pick-particular-versions-and-variants

[Luthaf]

Thanks for the explanation! 🙏