I upgraded to Fedora 39 and the open source application code_saturne I am working on is no longer capable of running in parallel with the OpenMPI library. No code changes have been made but just a recompilation on Fedora 39. I can see the various tasks running in the background but they do nothing. Also no error messages are generated and the code runs properly in serial mode.
I switched to the MPICH library and now the code runs properly as before. I think that something in broken in the OpenMPI library on Fedora 39.