https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/ Issue: games-simulation/simutrans-123.0.1-r1 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
Created attachment 792245 [details] build.log build log and emerge --info
Error(s) that match a know pattern in addition to what has been reported in the summary: ./configure: line 5531: svn: command not found fatal: not a git repository (or any parent up to mount point /var/tmp) dataobj/translator.cc:162:107: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing[https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wstrict-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
Added workaround in pull request, reported issue upstream: <https://forum.simutrans.com/index.php/topic,21836.0.html>.
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=b3d64bd03379c7214b8eb6457d88a8cf6558bc8e commit b3d64bd03379c7214b8eb6457d88a8cf6558bc8e Author: Ronny (tastytea) Gutbrod <gentoo@tastytea.de> AuthorDate: 2022-08-07 17:41:31 +0000 Commit: Joonas Niilola <juippis@gentoo.org> CommitDate: 2022-08-28 08:22:10 +0000 games-simulation/simutrans: append -fno-strict-aliasing Closes: https://bugs.gentoo.org/859229 Signed-off-by: Ronny (tastytea) Gutbrod <gentoo@tastytea.de> Signed-off-by: Joonas Niilola <juippis@gentoo.org> games-simulation/simutrans/simutrans-123.0.1-r1.ebuild | 1 + 1 file changed, 1 insertion(+)