https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/ Issue: dev-lang/rust-1.62.0 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
Created attachment 789413 [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: -- Could NOT find OCaml (missing: OCAMLFIND OCAML_VERSION OCAML_STDLIB_PATH) -- Could NOT find Python module pygments -- Could NOT find Python module pygments.lexers.c_cpp -- Could NOT find Python module yaml 297 | declare_error_trait!(Error: Sized + StdError); 832 | error::Error::description(self).fmt(f) FAILED: bin/dsymutil RuntimeError: failed to run: /var/tmp/portage/dev-lang/rust-1.62.0/work/rustc-1.62.0-src/build/bootstrap/debug/bootstrap build -vv --config=/var/tmp/portage/dev-lang/rust-1.62.0/work/rustc-1.62.0-src/config.toml -j16 warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string() /var/tmp/portage/dev-lang/rust-1.62.0/work/rustc-1.62.0-src/src/llvm-project/llvm/include/llvm/DWARFLinker/DWARFLinker.h:25: error: type ‘llvm::AccelTableKind’ violates the C++ One Definition Rule [-Werror=odr]
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 1.62.1 - Updating summary.