https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/ Issue: media-sound/mixxx-2.3.3 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 794165 [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: -- Could NOT find FFMPEG (missing: FFMPEG_LIBRARIES FFMPEG_INCLUDE_DIRS FFMPEG_libavcodec_LIBRARIES FFMPEG_libavcodec_INCLUDE_DIRS FFMPEG_libavformat_LIBRARIES FFMPEG_libavformat_INCLUDE_DIRS FFMPEG_libavutil_LIBRARIES FFMPEG_libavutil_INCLUDE_DIRS FFMPEG_libswresample_LIBRARIES FFMPEG_libswresample_INCLUDE_DIRS) -- Could NOT find KeyFinder (missing: KeyFinder_LIBRARY KeyFinder_INCLUDE_DIR) (Required is at least version "2.2.6") -- Could NOT find MAD (missing: MAD_LIBRARY MAD_INCLUDE_DIR) -- Could NOT find MP4 (missing: MP4_LIBRARY MP4_INCLUDE_DIR) -- Could NOT find MP4v2 (missing: MP4v2_LIBRARY MP4v2_INCLUDE_DIR) -- Could NOT find Modplug (missing: Modplug_LIBRARY Modplug_INCLUDE_DIR) -- Could NOT find Opus (missing: OpusFile_LIBRARY OpusFile_INCLUDE_DIR) -- Could NOT find ccache (missing executable) -- Could NOT find lilv (missing: lilv_LIBRARY lilv_INCLUDE_DIR) -- Could NOT find wavpack (missing: wavpack_LIBRARY wavpack_INCLUDE_DIR) FAILED: CMakeFiles/Kaitai.dir/lib/kaitai/kaitaistream.cpp.o /var/tmp/portage/media-sound/mixxx-2.3.3/work/mixxx-2.3.3/lib/kaitai/kaitaistream.cpp:258:37: error: dereferencing type-punned pointer will break strict-aliasing rules [-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
lto_tinderbox has reproduced this issue with version 2.3.3-r1 - Updating summary.
can't reproduce with 2.3.6, closing.
