Package: libopenmpi3 Version: 4.0.3-6 Severity: serious Hi Alastair,
I just managed by accident to do a partial upgrade of openmpi, i.e. openmpi-bin was still the buster version while libopenmpi3 was already upgraded to bullseye. This caused mpirun to segfault ... I could reproduce it in a minimal buster chroot, installing openmpi-bin/buster and thereafter enabling bullseye sources and upgrading libgcc-8-dev gcc-8-base libmpx2 libc6-dev libopenmpi3 to bullseye. gdb says, the segfault happened in opal_hwloc_base_get_nbobjs_by_type () from /usr/lib/x86_64-linux-gnu/libopen-pal.so.40 so this is likely because mpirun causes both libhwloc.so.5 (own dependency) and libhwloc.so.15 (libopen-rte.so.40 dependency) to be loaded in the same process. libopenmpi3 should probably break packages from buster depending on both libopenmpi3 and libhwloc5. Luckily there are not that many: gromacs-openmpi (<< 2020~beta2-2) (*) libeztrace0 (<< 1.1-8-5+b1) (**) openmpi-bin (<< 4.0.2-4+b1) (**) starpu-contrib-examples (<< 1.3.2+dfsg-2+b1) (*) starpu-examples (<< 1.3.2+dfsg-4+b1) (**) I haven't tried if they cause crashes as well ... I just tried to find the first version no longer depending on libhwloc5 (either because it switched to libhwloc15 (*) or because it just dropped the dependency (**)). So I would recomend to add these to libopenmpi3: Breaks: gromacs-openmpi (<< 2020~beta2-2), libeztrace0 (<< 1.1-8-5+b1), openmpi-bin (<< 4.0.2-4+b1), starpu-contrib-examples (<< 1.3.2+dfsg-2+b1), starpu-examples (<< 1.3.2+dfsg-4+b1) (They can go with the next soname bump or after bullseye was released). Andreas
