Buddy checkpointing does not work with hybrid API
There are no tests for the combination of hybrid (MPI + OpenMP) API and buddy checkpointing, but one of the existing tests (e.g.
test_buddy___1) can be adapted by changing all occurences of
parclose_ompi. The resulting test deadlocks, because the
execute_scatter implementations for the hybrid API do not make the same three branch comparison (collector, sender, no-op) as the MPI implementation (no-op is missing).