try to improve serialization test

4 jobs for misc_fixes in 5 minutes and 14 seconds (queued for 48 seconds)
Status Name Job ID Coverage
  Test
passed test_min #165869

00:01:51

passed test_mpi #165870

00:03:44

passed test_mpi_fftw #165871

00:03:54

passed test_mpi_fftw_hdf5 #165872

00:05:08

57.0%