https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/ Issue: app-emulation/virt-viewer-11.0 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 800025 [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: /usr/lib/gcc/x86_64-pc-linux-gnu/12.1.1/../../../../x86_64-pc-linux-gnu/bin/ld: /usr/lib64/libgtk-vnc-2.0.so: undefined reference to `gdk_wayland_display_get_type' /usr/lib/gcc/x86_64-pc-linux-gnu/12.1.1/../../../../x86_64-pc-linux-gnu/bin/ld: /usr/lib64/libspice-client-gtk-3.0.so: undefined reference to `gdk_wayland_display_get_wl_display' /usr/lib/gcc/x86_64-pc-linux-gnu/12.1.1/../../../../x86_64-pc-linux-gnu/bin/ld: /usr/lib64/libspice-client-gtk-3.0.so: undefined reference to `gdk_wayland_window_get_type' FAILED: src/remote-viewer FAILED: src/virt-viewer FAILED: tests/test-hotkeys Run-time dependency govirt-1.0 found: NO (tried pkgconfig and cmake) Run-time dependency rest-0.7 found: NO (tried pkgconfig and cmake) collect2: error: ld returned 1 exit status
This has nothing to do with LTO, and reproduces quite well with LTO disabled.
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=14f4be4038afc5a9ffd1a6693469b930cba8f67c commit 14f4be4038afc5a9ffd1a6693469b930cba8f67c Author: Eli Schwartz <eschwartz93@gmail.com> AuthorDate: 2024-05-05 20:44:33 +0000 Commit: Eli Schwartz <eschwartz@gentoo.org> CommitDate: 2024-08-06 00:18:24 +0000 net-libs/gtk-vnc: prevent automagically building against gtk[X,wayland] e.g. the upstream code checks whether GDK_WINDOWING_WAYLAND is defined by the gtk headers, and if so will compile against the wayland symbols it provides. This means that gtk-vnc built on a system with gtk+[-wayland] will be compatible with anything, but when built on a system with gtk+[wayland], requires that at runtime. This cannot be expressed with USE flags. We could bind tightly to whether gtk was built with wayland (and X), and in the process, arbitrarily restrict gtk-vnc[-wayland] to only build and install on a system with gtk+[-wayland]. But we recently added a hack to gtk itself which allows hiding the automagic macros entirely. Inject this via append-cflags if the USE flags aren't set, to simulate building on a system with more minimal gtk packages. Bug: https://bugs.gentoo.org/624960 Closes: https://bugs.gentoo.org/865659 Signed-off-by: Eli Schwartz <eschwartz93@gmail.com> Signed-off-by: Eli Schwartz <eschwartz@gentoo.org> net-libs/gtk-vnc/gtk-vnc-1.3.1-r1.ebuild | 63 ++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+)
