DOC small documentation changes in the advanced installation guide

[marenwestermann]

Reference Issues/PRs

follow up from PR #26334
towards #25985

What does this implement/fix? Explain your changes.

• makes pip install commands uniform in the contributing to scikit-learn documentation
• adds short explanation for why the --no-use-pep517 flag is needed when building from source

Any other comments?

ping @Micky774

[marenwestermann]

@Micky774 after reading the PEP 517 documentation I still don't have a good understanding of what it does. So I just added a short explanation for why it is needed when building from source. Let me know if it's correct or if you would like to see any other changes.

[Micky774]

@adrinjalali @marenwestermann do either of you have a link to a discussion regarding the necessity of --no-use-pep517 with --no-build-isolation? I think it would be good to link it in the note addendum in this PR.

[adrinjalali]

I'm not sure, but it seems pep517 is the pyproject.toml style kinda thing, for which editable mode is not allowed?

pypa/pip#6442

I really don't know why, but it seems they're related. There are a lot of related issues on the pip repo, and they don't give me a good explanation. So I'm not sure how we can explain it here lol

[glemaitre]

Are we sure that the PEP517 flag is necessary?

I created an environment from scratch and tried the instruction and it seems to work.
I might have a recent pip and I don't know if the implementation of the PEP660 solved the problem.

Here is the end of the output of my installation:

Editable install will be performed using a meta path finder.

  Options like `package-data`, `include/exclude-package-data` or
  `packages.find.exclude/include` may have no effect.

  adding '__editable___scikit_learn_1_4_dev0_finder.py'
  adding '__editable__.scikit_learn-1.4.dev0.pth'
  creating '/tmp/pip-wheel-5fmi1pu2/.tmp-pxhfybdj/scikit_learn-1.4.dev0-0.editable-cp39-cp39-linux_x86_64.whl' and adding '/tmp/tmpf4n112bkscikit_learn-1.4.dev0-0.editable-cp39-cp39-linux_x86_64.whl' to it
  adding 'scikit_learn-1.4.dev0.dist-info/COPYING'
  adding 'scikit_learn-1.4.dev0.dist-info/METADATA'
  adding 'scikit_learn-1.4.dev0.dist-info/WHEEL'
  adding 'scikit_learn-1.4.dev0.dist-info/top_level.txt'
  adding 'scikit_learn-1.4.dev0.dist-info/RECORD'
  /home/glemaitre/miniconda3/envs/sklearn-env/lib/python3.9/site-packages/setuptools/command/editable_wheel.py:348: InformationOnly: Editable installation.
  !!

          ********************************************************************************
          Please be careful with folders in your working directory with the same
          name as your package as they may take precedence during imports.
          ********************************************************************************

  !!
    wheel_obj.write_files(unpacked)
  Building editable for scikit-learn (pyproject.toml) ... done
  Created wheel for scikit-learn: filename=scikit_learn-1.4.dev0-0.editable-cp39-cp39-linux_x86_64.whl size=6794 sha256=ce84def516ebb2249d15425ed2686a4d2725cbb503bc7a131698042c908d7bf6
  Stored in directory: /tmp/pip-ephem-wheel-cache-g_whz2ov/wheels/ee/6e/16/0f21158be67077cef3936c48c77c622576e2a4aca15b696e07
Successfully built scikit-learn
Installing collected packages: threadpoolctl, joblib, scikit-learn
Successfully installed joblib-1.2.0 scikit-learn-1.4.dev0 threadpoolctl-3.1.0

[Micky774]

Are we sure that the PEP517 flag is necessary?

That's what I'm doubting as well. I believe at some point in discussion @rgommers mentioned that it should not be necessary nowadays (I don't recall the specifics). I'm not sure it is actually required at this point, or if it is required only in specific cases?

[glemaitre]

if it is required only in specific cases

With old pip version certainly.

[adrinjalali]

Yes, we definitely need the pep517 flag. Without the flag, every build will take as long as a fresh build, instead of only building the changed files. You can replicated that by trying it twice.

[glemaitre]

You can replicated that by trying it twice.

Oh I see. Since I am always using make in whenever rebuilding, I never saw this aspect.

[Micky774]

I'm okay with merging the PR as-is. We can always include additional notes later if we have some phrasing we'd really like to communicate to users.

[Micky774]

Thank you very much @marenwestermann 😄!

[marenwestermann]

Thanks a lot everyone for the discussion! :)