https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/ Issue: sci-libs/vtk-9.1.0-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
Created attachment 796885 [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 in addition to what has been reported in the summary: FAILED: lib64/libvtkParallel-9.1.so.9.1.0 /var/tmp/portage/sci-libs/vtk-9.1.0-r2/work/VTK-9.1.0/IO/AMR/vtkAMRFlashReaderInternal.h:77:16: error: type ‘struct tagBlock’ violates the C++ One Definition Rule [-Werror=odr]
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=2e02cfbf0edd45b41747e2707fc56b7512c6aef6 commit 2e02cfbf0edd45b41747e2707fc56b7512c6aef6 Author: Bernd Waibel <waebbl-gentoo@posteo.net> AuthorDate: 2022-08-23 16:54:15 +0000 Commit: Sam James <sam@gentoo.org> CommitDate: 2022-09-01 02:23:53 +0000 sci-libs/vtk: build with LTO enabled Closes: https://bugs.gentoo.org/863038 Signed-off-by: Bernd Waibel <waebbl-gentoo@posteo.net> Closes: https://github.com/gentoo/gentoo/pull/27010 Signed-off-by: Sam James <sam@gentoo.org> ...-or-scope-struct-names-to-avoid-conflicts.patch | 126 +++++++++++++++++++++ sci-libs/vtk/vtk-9.1.0-r2.ebuild | 1 + 2 files changed, 127 insertions(+)
