[mpich-discuss] MPICH2 and Python

[ddkrause]

Hello everybody,

today I had the pleasure to track down a bug in my software which caused an
error int MPI_Comm_rank due to an invalid communicator.

The interesting point is that this only occurs if I include <Python.h>
*before* <mpi.h> . There is no problem If i included it not or after
<mpi.h>. Is this a known problem?

I looked into the preprocessor output but couldn't find a significant
difference. It seems that no Python macro overwrites some of the MPICH
stuff (they both use a seperate namespace anyway).

Any idea what's going on? I'm using mpich2-1.07.

I have no problem in interchanging the include ordering but I think it's
interesting to find the reason. Maybe it helps me to understand some
more internal details of MPICH.

Thanks & Best regards,
Dorian Krause

PS: Due to the bunch of software I'm using here I think its not helpful
to include the source code but I can send it if it helps.