https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/ Issue: sys-libs/glibc-2.36-r5 fails tests (LTO-SYSTEM). Discovered on: amd64 (internal ref: lto_tinderbox) NOTE: (LTO-SYSTEM) in the summary means that bug was found on a machine that runs lto but this bug MAY or MAY NOT BE related to lto. 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
Created attachment 829947 [details] build.log.xz build log and emerge --info (compressed because it exceeds attachment limit, use 'xzless' to read it)
Error(s) that match a know pattern: FAIL: math/test-float-j1 FAIL: math/test-float-y0 FAIL: math/test-float-y1 FAIL: math/test-float32-j1 FAIL: math/test-float32-y0 FAIL: math/test-float32-y1 FAIL: misc/tst-bz21269 FAIL: string/tst-wcsncmp-rtm sed: can't read /var/tmp/portage/sys-libs/glibc-2.36-r5/work/build-x86-x86_64-pc-linux-gnu-nptl/csu/32/crtn.o.dt: No such file or directory sh: line 1: echo: write error: Broken pipe
(In reply to Agostino Sarubbo from comment #2) > Error(s) that match a know pattern: > > > FAIL: math/test-float-j1 > FAIL: math/test-float-y0 > FAIL: math/test-float-y1 > FAIL: math/test-float32-j1 > FAIL: math/test-float32-y0 > FAIL: math/test-float32-y1 > FAIL: misc/tst-bz21269 > FAIL: string/tst-wcsncmp-rtm > sed: can't read > /var/tmp/portage/sys-libs/glibc-2.36-r5/work/build-x86-x86_64-pc-linux-gnu- > nptl/csu/32/crtn.o.dt: No such file or directory > sh: line 1: echo: write error: Broken pipe Given that glibc uses filter-flags and thus drops anything LTO-related, this feels fishy. Can't do anything without more details though (corresponding .out files from math/ directory)
