https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/ Issue: sys-boot/syslinux-6.04_pre1-r3 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 797824 [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: /var/tmp/portage/sys-boot/syslinux-6.04_pre1-r3/work/syslinux-6.04-pre1/memdisk/start32.S:77: undefined reference to `setup' /var/tmp/portage/sys-boot/syslinux-6.04_pre1-r3/work/syslinux-6.04-pre1/memdisk/start32.S:84: undefined reference to `rm_args' /var/tmp/portage/sys-boot/syslinux-6.04_pre1-r3/work/syslinux-6.04-pre1/memdisk/start32.S:89: undefined reference to `rm_args' EACCES (13) => "Permission denied" ENOENT (2) => "No such file or directory" x86_64-pc-linux-gnu-ld: /var/tmp/portage/sys-boot/syslinux-6.04_pre1-r3/work/syslinux-6.04-pre1/memdisk/start32.S:78: undefined reference to `rm_args'
The build system calls ld directly, which results in warnings like this: > x86_64-pc-linux-gnu-ld -m elf_i386 -o memdisk32.elf -T /var/tmp/portage/sys-boot/syslinux-6.04_pre1-r3/work/syslinux-6.04-pre1/memdisk/i386/memdisk.ld start32.o setup.o msetup.o e820func.o conio.o memcpy.o memset.o memmove.o unzip.o dskprobe.o eltorito.o ctypes.o strntoumax.o strtoull.o suffix_number.o memdisk_chs_512.o memdisk_edd_512.o memdisk_iso_512.o memdisk_iso_2048.o > x86_64-pc-linux-gnu-ld: setup.o: plugin needed to handle lto object I think we would either need to link using the cc frontend, or disable lto by mangling CFLAGS.
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=457a408fd47cc48950a5c7cd86ed99c3c42206ce commit 457a408fd47cc48950a5c7cd86ed99c3c42206ce Author: Ian Jordan <immoloism@gmail.com> AuthorDate: 2022-11-18 03:15:53 +0000 Commit: Sam James <sam@gentoo.org> CommitDate: 2022-12-24 07:05:41 +0000 sys-boot/syslinux: Filter LTO Syslinux can only use LTO when using the ffat-lto-objects cflag and as this is a hack solution I recommend filtering which seems to be the only way to do it without. Closes: https://bugs.gentoo.org/863722 Signed-off-by: Ian Jordan <immoloism@gmail.com> Closes: https://github.com/gentoo/gentoo/pull/28318 Signed-off-by: Sam James <sam@gentoo.org> sys-boot/syslinux/syslinux-6.04_pre1-r4.ebuild | 4 +++- sys-boot/syslinux/syslinux-6.04_pre1-r5.ebuild | 4 +++- sys-boot/syslinux/syslinux-6.04_pre3-r1.ebuild | 4 +++- 3 files changed, 9 insertions(+), 3 deletions(-)