[FLASH-USERS] Fatal error in MPI_Comm_create when I run Flash on Mac os x

[Klaus Weide]

On Mon, 8 Jul 2013, Reem Alraddadi wrote:

> I am running FLASH4 on Mac os x version 10.7.5 and I am using mpich-3.0.4
> and I got the following error:
> 
> Fatal error in MPI_Comm_create: Other MPI error, error stack:
> MPI_Comm_create(600)..........
> .......: MPI_Comm_create(comm=0x84000002, group=0xc8001349,
> new_comm=0x7fff606a8614) failed
  ..... 
> People from mpich suggested that I should  free unsed communicators. 

FLASH in general deallocates the communicators that it allocates.
I am not aware of any released version of FLASH 4 with a communicator leak 
in the FLASH code.

Are you perhaps trying to use FLASH with the hypre library?
(You did not supply any information on what kind of simulation
you have configured, which code units are included etc.)
I know of a communicator leak problem in the FLASH4 + hypre-2.9.0b
combination. If this is what you are trying to use, I suggest
downgrading hypre to 2.8.0b or 2.7.0b as a solution.

> So I
> added in  Flash_mpi.h the following line:
>    integer, parameter :: FLASH_COMM = MPI_COMM_FREE

This change does not make much sense to me.

Klaus