https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/ Issue: sys-devel/gdb-12.1-r1 fails to compile. Discovered on: amd64 (internal ref: tinderbox) NOTE: This machine uses lto with CFLAGS=-flto -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing
Created attachment 787118 [details] build.log.xz build log and emerge --info (compressed because it exceeds attachment limit, use 'xzless' to read it)
Upstream are working on the ODR violations. Bunch fixed in master but not this one yet.
(In reply to Agostino Sarubbo from comment #0) > Discovered on: amd64 (internal ref: tinderbox) internal ref is: lto_tinderbox
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
lto_tinderbox has reproduced this issue with version 12.1-r2 - Updating summary.
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=0262b1c837e178a7d955d13f463d8ce648ee00ad commit 0262b1c837e178a7d955d13f463d8ce648ee00ad Author: Sam James <sam@gentoo.org> AuthorDate: 2023-08-13 10:35:11 +0000 Commit: Sam James <sam@gentoo.org> CommitDate: 2023-08-13 23:38:01 +0000 sys-devel/gdb: filter-lto Lots of LTO warnings acknowledged upstream. Closes: https://bugs.gentoo.org/853898 Signed-off-by: Sam James <sam@gentoo.org> sys-devel/gdb/gdb-13.2-r2.ebuild | 3 +++ sys-devel/gdb/gdb-9999.ebuild | 3 +++ 2 files changed, 6 insertions(+)
There's some upstream activity so this may even get fixed for 14...
