I built mpich2 before with gcc and Intel compilers. I tried to compile with open64, so first tried mpich2-1.2.1p1 which I built with other compilers. The make proceeds, I see lot of CC commands, then at the first F90, it falls over. So I added the verbosity option V=1 to the make and tried again. When it got up to the offending "F90 mpi.f90" stage, I now see this at the tail of the make log: date > .libstamp1 make[4]: Leaving directory `/home/michael/apps/thirdparty/mpich2-1.2.1p1/src/binding/f90' make[4]: Entering directory `/home/michael/apps/thirdparty/mpich2-1.2.1p1/src/binding/f90' false -O2 -I. -c mpi.f90 -o _smpi.o mv -f _smpi.o mpi.lo make[4]: *** [mpi.lo] Error 1 make[4]: Leaving directory `/home/michael/apps/thirdparty/mpich2-1.2.1p1/src/binding/f90' make[3]: *** [all-redirect] Error 1 make[3]: Leaving directory `/home/michael/apps/thirdparty/mpich2-1.2.1p1/src/binding/f90' make[2]: *** [all-redirect] Error 1 make[2]: Leaving directory `/home/michael/apps/thirdparty/mpich2-1.2.1p1/src/binding' make[1]: *** [all-redirect] Error 2 make[1]: Leaving directory `/home/michael/apps/thirdparty/mpich2-1.2.1p1/src' make: *** [all-redirect] Error 2 So "F90" has become "false" somewhere along the track. Configure variables were for 1.2.1p1: BUILD_DIR=/usr/local F90=openf90 F77=openf90 CC=opencc CXX=openCC CFLAGS="-fPIC -O" FFLAGS="-fPIC -fno-second-underscore -O" F90FLAGS="-fPIC -fno-second-underscore -O" FLAGS="--prefix=${BUILD_DIR} --enable-threads --enable-sharedlibs=gcc \ --enable-f77 --enable-f90 --enable-cxx" Next, I tried version 1.4 of mpich2, which requires changing a few things, such as F90 to FC and --enable-f90 to --enable-fc and adding --enabled-shared to flags. I used these configure variables with versions 1.3 to 1.5: BUILD_DIR=/usr/local F77=openf90 FC=openf90 CC=opencc CXX=openCC CFLAGS="-fPIC -O" FFLAGS="-fPIC -fno-second-underscore -O" FCFLAGS="-fPIC -fno-second-underscore -O" F77FLAGS="-fPIC -fno-second-underscore -O" FLAGS="--prefix=${BUILD_DIR} --enable-threads --enable-sharedlibs=gcc \ --enable-fc --enable-shared --enable-f77 --enable-cxx" Again this flops when make gets up to mpi.f90. I still see "false" instead of the FC compiler command. Only version 1.5 of mpich2 can be built okay with open64 compilers. I used version 4.2.4 of open64 under RHEL 5.8 64-bit. I also tried open64 version 4.2.1 Has anybody found other combinations to build mpich2 using open64?