Hi,
I know this sounds crazy, but I was having segfaults with openmpi and, after many investigations, hair pulling, redoing the virtual machines, etc, I found that the segfault goes away if I remove the mesa package. Then I though I could just recompile it to check if it works, so I downloaded the official current slackbuild and surprisingly mesa does not build succesfully. I am using the latest current slackware64 version (Wed 26 2022). How can I track the root problem, which is very strange? I also has suspicions on the llvm packages since mesa also says something like "undefined reference to `LLVMInitializeBPFTarget" but this goes way out of my league.

FULL DETAILS

This is the original segfault from mpi (version 4.1.0 and 4.1.2 tested, installed with sbopkg, even after recompiling and using the latest version for hwloc)

```
The, after just `slackpkg remove mesa` (a tip after running gdb mpirun), the output from the same command is

So mpirun works without mesa. Then, I downloaded the mesa.SlackBuild stuff from https://mirrors.slackware.com/slackw...source/x/mesa/ , I tried to recompile mesa (tested 21.3.{1,2,...,5} versions) and I get an error with libMesaOpenCL

Have you seen this?

Perhaps rebuilding LLVM without -DBUILD_SHARED_LIBS=ON (the Slackware default) and with the options discussed here is required.

Excellent search skills thanks.
Yes, after following the links you posted, I recompiled LLVM with DLYB on, and then mesa compiled in current! But the problem with openmpi persists. I tried also recompiling llvm, then mesa, then openmpi, same problem. There must be some interdependence which is above my understanding. For now, and given that we are using the computers remotely, I will just keep mesa uninstalled. Also I will use the opempi implementation from spack.
Thanks for your help