issues with gfortran43/44 and mpich

I am finally getting to the bottom of what has been going wrong with re-compiling MPICH for F90/F95 (required for CASTEP - a demanding Fortran code). I have now narrowed it down to one issue between recompiling MPICH with gfortran43/44 for SL5 usage with CASTEP instead of plain old gfortran.

FC="gfortran44" ; export FC;
F90="gfortran44" ; export F90;
...
--enable-f90modules

The SAM MPICH test runs after recompiling with F90 support using gfortran and in fact it works fine on SL4 and SL5. So that was not the issue.

message size            transfertime            bandwidth
32 bytes                0.000000 sec            inf MB/s
2048 bytes              0.000117 sec            17.476267 MB/s
131072 bytes            0.001445 sec            90.687654 MB/s
8388608 bytes           0.078437 sec            106.946397 

It turns out that MPICH just doesn't work when compiled with gfortran43/44. Leaving me in a bit of an pickle as CASTEP will not compile on SL5 with gfortran, you have to use gfortran43/44!

Time for the backup plan ..... openmpi.