Attached debdiff for mpich 5.0.1-9ubuntu1 on stonking. Fixes the root cause flag leakage: - Exports MPICHLIB_LDFLAGS and passes LDFLAGS="" FFLAGS="$(GF_FLAGS)" FCFLAGS="$(GF_FLAGS)" to dh_auto_configure. - Drops @LDFLAGS@ from WRAPPER_LIBS in MPL localdefs.in to keep mpich.pc clean.
Verified in a clean stonking container: all compiler wrappers (mpicxx, mpicc, mpifort) and mpich.pc are clean of distribution LTO and metadata flags. madness compiles cleanly against the rebuilt mpich. Forwarded to Debian BTS: https://bugs.debian.org/1150548 ** Description changed: - madness fails to build from source in Ubuntu 26.10 (stonking) due to - space-delimited MPI compile flags passed into target_compile_options as - a single argument: + This bug tracks FTBFS of madness and compiler flag leakage from mpich in + Ubuntu 26.10 (stonking). - cc1plus: error: unrecognized argument to '-flto=' option: 'auto -ffat- - lto-objects' + [ mpich: Root Cause Fix ] + mpich leaks distribution build flags into compiler wrappers and pkg-config: + 1. debian/rules exports MPICHLIB_*FLAGS for library build, but does not isolate LDFLAGS: + - MPICHLIB_LDFLAGS is not exported. + - LDFLAGS is not cleared in dh_auto_configure, causing WRAPPER_LDFLAGS=$LDFLAGS. + - FFLAGS="$(FFLAGS)" passes optimization and LTO flags into WRAPPER_FFLAGS/WRAPPER_FCFLAGS. + 2. MPL localdefs.in unconditionally appends @LDFLAGS@ to WRAPPER_LIBS, leaking Ubuntu flags (-flto=auto, -Wl,--package-metadata=...) into mpich.pc (Libs:). - Root cause: - MPI_COMPILE_FLAGS returned by CMake FindMPI contains multiple compiler options (such as '-flto=auto -ffat-lto-objects' from mpich wrappers). In src/madness/CMakeLists.txt, target_compile_options(madness PUBLIC "${MPI_COMPILE_FLAGS}") passes the variable with quotes and without separate_arguments(), causing CMake to pass the entire string as a single command-line option to g++. + Fix for mpich: + - Export MPICHLIB_LDFLAGS and pass LDFLAGS="" FFLAGS="$(GF_FLAGS)" FCFLAGS="$(GF_FLAGS)" to dh_auto_configure. + - Add debian/patches/mpl-isolate-ldflags.patch to remove @LDFLAGS@ from WRAPPER_LIBS in MPL localdefs.in. + - Debian BTS: https://bugs.debian.org/1150548 - Fix: - 1. Run separate_arguments(MPI_COMPILE_FLAGS) in external/mpi.cmake to split the flags into a CMake list. - 2. Drop quotes in target_compile_options(madness PUBLIC ${MPI_COMPILE_FLAGS}) in src/madness/CMakeLists.txt. - 3. Clean config/config.guess and config/config.sub via debian/clean to ensure clean source build. + [ madness: Consumer Fix ] + madness CMakeLists.txt passes "${MPI_COMPILE_FLAGS}" as a quoted string to target_compile_options(madness PUBLIC ...). When multiple flags are returned by FindMPI, g++ rejects the space-separated string as a single invalid argument: + cc1plus: error: unrecognized argument to '-flto=' option: 'auto -ffat-lto-objects' - Debian BTS: - https://bugs.debian.org/1150537 - - Verification: - Built madness successfully on Ubuntu 26.10 amd64. All static libraries and test executables compiled and linked cleanly. - + Fix for madness: + - Split MPI_COMPILE_FLAGS using separate_arguments() in external/mpi.cmake. + - Drop quotes in target_compile_options() in src/madness/CMakeLists.txt. + - Clean config.guess/config.sub via debian/clean. + - Debian BTS: https://bugs.debian.org/1150537 --- [ Original Report ] - - madness 0.10.1+git20200818.eee5fd9f-4 has been stuck in stonking-proposed for ~346 days. update_excuses reports: + madness 0.10.1+git20200818.eee5fd9f-4 has been stuck in stonking- + proposed for ~346 days. update_excuses reports: missing build on amd64/amd64v3/arm64/ppc64el/s390x: libmadness-dev (from 0.10.1+git20200818.eee5fd9f-3) Build log (amd64): https://launchpad.net/ubuntu/+source/madness/0.10.1+git20200818.eee5fd9f-4/+build/32793501 Failure (7 times, in src/madness/{world,tensor,mra,misc}): cc1plus: error: unrecognized argument to '-flto=' option: 'auto -ffat- lto-objects' The failing compile lines contain the LTO flags as ONE quoted argument: /usr/bin/x86_64-linux-gnu-g++ ... -std=c++17 -fPIC "-flto=auto -ffat- lto-objects" -MD ... so g++ sees "-flto=" with the value "auto -ffat-lto-objects". Only the MPI-using targets are affected (the bundled gtest/muParser/tinyxml targets build fine), and the build used cmake 4.3.4-1ubuntu1, gcc-15 15.3.0-4ubuntu1. Cause (analysis, to be confirmed): The flag does not come from madness itself: debian/rules doesn't set any LTO option and madness' CMake files don't add -flto. It comes from MPICH. madness Build-Depends on libmpich-dev and uses CMake's FindMPI, which interrogates the mpicxx wrapper and turns what it finds into MPI_CXX_COMPILE_OPTIONS / the MPI::MPI_CXX interface target. In stonking, mpich 5.0.1-9 (synced from Debian) bakes the LDFLAGS it was built with into its wrappers and pkg-config file. On Ubuntu those LDFLAGS contain our default LTO flags: /usr/bin/mpicxx.mpich: final_ldflags=" -Wl,-Bsymbolic-functions -Wl,--package-metadata=... -flto=auto -ffat-lto-objects -Wl,-z,relro -Wl,-z,now ..." /usr/lib/x86_64-linux-gnu/mpich/lib/pkgconfig/mpich.pc: Libs: ... -flto=auto -ffat-lto-objects ... fflags= / fcflags= ... -flto=auto -ffat-lto-objects ... FindMPI then ends up passing "-flto=auto -ffat-lto-objects" as a single compile option. Debian doesn't enable LTO by default, so its mpich wrappers are clean and madness builds there (Debian testing has the -4 binaries). That makes this Ubuntu-specific. (mpich's debian/rules explicitly clears CPPFLAGS/CFLAGS/CXXFLAGS for configure, using MPICHLIB_*FLAGS for the library build instead, but does not do the same for LDFLAGS, which is presumably how the LTO flags leak into the wrappers.) Debian / upstream status: - No open Debian bug against madness (or found against mpich) for this; it is Ubuntu-only because of LTO. - madness upstream is a 2020 git snapshot; nothing to pick up there for this. Suggested direction (to be done by whoever picks this up): 1. Reproduce: build madness -4 in a stonking chroot/container and confirm the quoted flag comes from MPI::MPI_CXX (e.g. check MPI_CXX_COMPILE_OPTIONS in CMakeCache.txt, and "mpicxx.mpich -show"). 2. Quick unblock for madness: add an Ubuntu delta to debian/rules export DEB_BUILD_MAINT_OPTIONS = optimize=-lto This might not be enough on its own, since the flags come from mpicxx, not from madness' own build flags; if so, sanitise MPI_CXX_COMPILE_OPTIONS (e.g. pass -DMPI_CXX_COMPILE_OPTIONS= / -DMPI_CXX_SKIP_MPICXX..., or override at configure time). 3. Proper fix: mpich should not leak the build's LDFLAGS (LTO, -Wl,--package-metadata, -Bsymbolic-functions, ...) into mpicc/mpicxx/mpifort and mpich.pc, e.g. by building with MPICHLIB_LDFLAGS and an empty LDFLAGS for configure, like it already does for CFLAGS. That would be an Ubuntu delta for mpich (or a Debian bug, since the package-metadata/relro flags leak there too) and would also protect other CMake+MPICH reverse build-dependencies. Check whether other mpich users in proposed fail the same way before deciding. 4. Then upload/retry madness and check the autopkgtests. ** Changed in: mpich (Ubuntu) Status: New => Confirmed ** Bug watch added: Debian Bug tracker #1150548 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1150548 ** Changed in: mpich (Debian) Remote watch: None => Debian Bug tracker #1150548 ** Patch added: "mpich 5.0.1-9ubuntu1 debdiff for stonking" https://bugs.launchpad.net/bugs/2170321/+attachment/6007965/+files/mpich_5.0.1-9ubuntu1_stonking.debdiff -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2170321 Title: madness FTBFS in stonking: '-flto=auto -ffat-lto-objects' passed as one argument (LTO flags leaked by mpich wrappers) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/madness/+bug/2170321/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
