Bug 869476 – dev-python/pygal-3.0.4-r1 fails to compile (USE=doc): ModuleNotFoundError: No module named sphinx_rtd_theme

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description Agostino Sarubbo 2022-09-10 11:53:20 UTC]

https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/

Issue: dev-python/pygal-3.0.0-r2 fails to compile (lto).
Discovered on: amd64 (internal ref: lto_tinderbox)

NOTE:
This machine uses lto with CFLAGS=-flto -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing

Here is a bit of explanation:

-Werror=lto-type-mismatch:
User to find possible runtime issues in packages. It likely means the package is unsafe to build & use with LTO.
For projects using the same identifier but with different types across different files, they must be fixed to be consistent across the codebase.

-Werror=odr:
Used to find possible runtime issues in packages. These bugs are a problem anyway but may be even worse when combined with LTO. C++ code must comply with the One Definition Rule (ODR) - see https://en.cppreference.com/w/cpp/language/definition#One_Definition_Rule.

-Werror=strict-aliasing:
Used to find possible runtime issues in packages. These bugs are a problem anyway but may be even worse when combined with LTO.

Workarounds:
- If upstream is friendly and still active, file a bug upstream. For emulators, codecs, games, or multimedia packages, it may be worth just applying a workaround instead, as upstreams sometimes aren't receptive to these bugs (VALID FOR ALL).
- Use the new 'filter-lto' from flag-o-matic.eclass as it's likely to be unsafe with LTO (VALID FOR lto-type-mismatch - odr).
- Fix it yourself if interested, of course (VALID FOR ALL).
- Append-flags -fno-strict-aliasing (VALID FOR strict-aliasing).
- Use memcpy() but a union is sometimes suitable too (VALID FOR strict-aliasing).
- -fstrict-aliasing is implied by -O2, so this must be addressed in some form (VALID FOR strict-aliasing).

See also: https://marc.info/?l=gentoo-dev&m=165639574126280&w=2

[Comment 1 Agostino Sarubbo 2022-09-10 11:53:22 UTC]

Created attachment 804442 [details]
build.log

build log and emerge --info

[Comment 2 Agostino Sarubbo 2023-02-17 08:58:32 UTC]

ci has reproduced this issue with version 3.0.0-r4 - Updating summary.

[Comment 3 Agostino Sarubbo 2023-12-27 08:48:18 UTC]

gcc14_tinderbox has reproduced this issue with version 3.0.4 - Updating summary.

[Comment 4 Agostino Sarubbo 2024-01-29 07:41:33 UTC]

ci has reproduced this issue with version 3.0.4-r1 - Updating summary.

[Comment 5 Eli Schwartz 2024-03-06 00:20:33 UTC]

Quite obviously a ModuleNotFoundError isn't an LTO compilation bug. Especially since the package contains no compiled code...

Note the actually important information here is that this is built with USE=doc, and the doc build failed.

[Comment 6 Larry the Git Cow 2024-03-06 03:37:32 UTC]

The bug has been closed via the following commit(s):

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=47f17a073e851205befc429e9a03fa71041135cd

commit 47f17a073e851205befc429e9a03fa71041135cd
Author:     Eli Schwartz <[e-mail]>
AuthorDate: 2024-03-06 00:17:15 +0000
Commit:     Sam James <[e-mail]>
CommitDate: 2024-03-06 03:36:20 +0000

    dev-python/pygal: fix dependencies for doc building
    
    A sphinx plugin wasn't specified, and therefore wasn't guaranteed to be
    installed.
    
    Closes: https://bugs.gentoo.org/869476
    Signed-off-by: Eli Schwartz <[e-mail]>
    Signed-off-by: Sam James <[e-mail]>

 dev-python/pygal/pygal-3.0.4-r1.ebuild | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)