All, Some of our users complained that Tau doesn't work with the latest version of mpich. After some investigation we discovered that this was an issue with the MPI-3 standard. Specifically, we added const bindings for many of the MPI functions. The thinking in the Forum was that this change is backward compatible since applications using MPI_Send don't have to change at all. However, this seems to be causing problems for tools that redefine MPI functions. Basically, a tool can no longer have a function like this: int MPI_Send(void *buf, int count, MPI_Datatype datatype, int dest, int tag, MPI_Comm comm) { /* Do magic */ ret = PMPI_Send(...); /* Do some more magic */ return ret; } The compiler will complain that this doesn't match the prototype in mpi.h which is: int MPI_Send(const void *buf, int count, MPI_Datatype datatype, int dest, int tag, MPI_Comm comm); Am I missing something here? Are all tools now required to have an #if MPI_VERSION >= 3 check? Does this mean that all existing tools are now broken for MPI-3 implementations? -- Pavan -- Pavan Balaji http://www.mcs.anl.gov/~balaji