build: show all cython warnings

[tornaria]

Motivated by https://github.com/sagemath/sage/pull/37792#issuecomment-2053663025, change cython configuration so we show all warnings.

This will lead to a number of warnings, but it's IMO better to know about that and works towards fixing as much warnings as possible (and we have a fair number of warnings that are indeed relevant and not just false positives).

:memo: Checklist

• [x] The title is concise and informative.
• [x] The description explains in detail what this PR is about.
• [x] I have linked a relevant issue or discussion.

[mkoeppe]

This change won't take effect for most people because the editable build (via src/setup.py) does not go through sage_build_cython

[github-actions[bot]]

Documentation preview for this PR (built with commit 4dbb878e4bfe83ed43879e919931850e78656788; changes) is ready! :tada: This preview will update shortly after each push to this PR.

[tornaria]

What is going on here:

  [sagemath_categories-10.4.beta4] [spkg-check] **********************************************************************
  [sagemath_categories-10.4.beta4] [spkg-check] File "sage/arith/power.pyx", line 49, in sage.arith.power.generic_power
  [sagemath_categories-10.4.beta4] [spkg-check] Failed example:
  [sagemath_categories-10.4.beta4] [spkg-check]     F = Zmod(5)
  [sagemath_categories-10.4.beta4] [spkg-check] Exception raised:
  [sagemath_categories-10.4.beta4] [spkg-check]     Traceback (most recent call last):
  [sagemath_categories-10.4.beta4] [spkg-check]       File "/sage/pkgs/sagemath-categories/.tox/sagepython-sagewheels-nopypi-norequirements/lib/python3.10/site-packages/sage/doctest/forker.py", line 714, in _run
  [sagemath_categories-10.4.beta4] [spkg-check]         self.compile_and_execute(example, compiler, test.globs)
  [sagemath_categories-10.4.beta4] [spkg-check]       File "/sage/pkgs/sagemath-categories/.tox/sagepython-sagewheels-nopypi-norequirements/lib/python3.10/site-packages/sage/doctest/forker.py", line 1146, in compile_and_execute
  [sagemath_categories-10.4.beta4] [spkg-check]         exec(compiled, globs)
  [sagemath_categories-10.4.beta4] [spkg-check]       File "<doctest sage.arith.power.generic_power[6]>", line 1, in <module>
  [sagemath_categories-10.4.beta4] [spkg-check]         F = Zmod(Integer(5))
  [sagemath_categories-10.4.beta4] [spkg-check]     NameError: name 'Zmod' is not defined
  [sagemath_categories-10.4.beta4] [spkg-check] **********************************************************************

  [sagemath_categories-10.4.beta4] [spkg-check] **********************************************************************
  [sagemath_categories-10.4.beta4] [spkg-check] File "sage/categories/additive_monoids.py", line 41, in sage.categories.additive_monoids.AdditiveMonoids
  [sagemath_categories-10.4.beta4] [spkg-check] Failed example:
  [sagemath_categories-10.4.beta4] [spkg-check]     C.Algebras(QQ).is_subcategory(AlgebrasWithBasis(QQ))
  [sagemath_categories-10.4.beta4] [spkg-check] Exception raised:
  [sagemath_categories-10.4.beta4] [spkg-check]     Traceback (most recent call last):
  [sagemath_categories-10.4.beta4] [spkg-check]       File "/sage/pkgs/sagemath-categories/.tox/sagepython-sagewheels-nopypi-norequirements/lib/python3.10/site-packages/sage/doctest/forker.py", line 714, in _run
  [sagemath_categories-10.4.beta4] [spkg-check]         self.compile_and_execute(example, compiler, test.globs)
  [sagemath_categories-10.4.beta4] [spkg-check]       File "/sage/pkgs/sagemath-categories/.tox/sagepython-sagewheels-nopypi-norequirements/lib/python3.10/site-packages/sage/doctest/forker.py", line 1146, in compile_and_execute
  [sagemath_categories-10.4.beta4] [spkg-check]         exec(compiled, globs)
  [sagemath_categories-10.4.beta4] [spkg-check]       File "<doctest sage.categories.additive_monoids.AdditiveMonoids[6]>", line 1, in <module>
  [sagemath_categories-10.4.beta4] [spkg-check]         C.Algebras(QQ).is_subcategory(AlgebrasWithBasis(QQ))
  [sagemath_categories-10.4.beta4] [spkg-check]     NameError: name 'QQ' is not defined
  [sagemath_categories-10.4.beta4] [spkg-check] **********************************************************************

etc...

[tornaria]

This change won't take effect for most people because the editable build (via src/setup.py) does not go through sage_build_cython

Why can't src/setup.py use the same code to build cython extensions? In any case, the same line can be added to src/setup.py.

The review question here is: what do you think about enabling all cython warnings as I suggest here? This adds a lot of cython warnings, but at least the Unraisable exception... warning seems a real problem (see https://github.com/sagemath/sage/pull/37792#issuecomment-2053663025 -- after all of those are fixed maybe this warning should be turned into an error).

[mkoeppe]

What is going on here:

  [sagemath_categories-10.4.beta4] [spkg-check] **********************************************************************

• that's #37750 -- broken again as a result of the big revert.
• fixed now.

[mkoeppe]

Why can't src/setup.py use the same code to build cython extensions?

Got to ask the author about that.

[tornaria]

The review question here is: what do you think about enabling all cython warnings as I suggest here? This adds a lot of cython warnings, but at least the Unraisable exception... warning seems a real problem (see https://github.com/sagemath/sage/pull/37792#issuecomment-2053663025 -- after all of those are fixed maybe this warning should be turned into an error).

[dimpase]

"unraiseable" should definitely be turned on.

warnings which are certainly bogus - better not. But OK, all on is good too.

[tornaria]

I updated the PR so that all cython warnings are enabled, both in sage_setup and in src/setup.py (for editable builds).

[mkoeppe]

Thanks! I'll try it out and take a look.

[mkoeppe]

The output from all the warnings seems somewhat excessive. Perhaps here we should at least try to fix the warnings that come in from the most commonly included .pxd files