I have a Julia test case on macOS where MPICH randomly gets stuck in MPI_Finalize (with about a 5% chance). See e.g. https://github.com/JuliaParallel/MPI.jl/runs/4357341818 Can you advise under what circumstances MPICH could get stuck there? The respective run uses 3 processes, and all 3 processes call into MPI_Finalize, but no process returns. I assume that MPI_Finalize contains internally the equivalent to an MPI_Barrier, but that should succeed here. Are there other actions taken in MPI_Finalize that would require some kind of consistent state across the application? For example, if a communicator was created on all processes, but freed only on some processes, could this cause such a deadlock? -erik -- Erik Schnetter <[email protected]> http://www.perimeterinstitute.ca/personal/eschnetter/