Was this change intentional? This way, code linked with "mpicc" is failing because of the missing symbol. IMHO, MPI_Status_c2f should be defined in libmpi.dylib. Not checked on Linux, but looking at the Homebrew formula, I cannot find anything obvious to indicate this is a brew and/or OS X issue: https://github.com/Homebrew/homebrew/blob/master/Library/Formula/mpich2.rb $ nm /usr/local/Cellar/mpich2/3.1.1/lib/libmpi.dylib | grep MPI_Status_c2f $ nm /usr/local/Cellar/mpich2/3.1.1/lib/libmpifort.dylib | grep MPI_Status_c2f 0000000000008d60 T _MPI_Status_c2f -- Lisandro Dalcin --------------- CIMEC (UNL/CONICET) Predio CONICET-Santa Fe Colectora RN 168 Km 472, Paraje El Pozo 3000 Santa Fe, Argentina Tel: +54-342-4511594 (ext 1016) Tel/Fax: +54-342-4511169