Hi, yesterday I tried to install mpich-master-v3.1.2-131-gfa09f8e3 on my machines (Solaris 10 Sparc, Solaris 10 x86_64, and openSUSE Linux 12.1 x86_64) with Sun C 5.12 and gcc-4.9.0 and failed with the following errors for gcc on my Solaris platforms as well. I configured once more with the following command. tyr mpich-3.1.3-SunOS.sparc.64_gcc 254 head -8 config.log | grep mpich $ ../mpich-master-v3.1.2-131-gfa09f8e3/configure --prefix=/usr/local/mpich-3.1.3_64_gcc --libdir=/usr/local/mpich-3.1.3_64_gcc/lib64 --includedir=/usr/local/mpich-3.1.3_64_gcc/include64 CC=gcc CXX=g++ F77=gfortran FC=gfortran CFLAGS=-m64 CXXFLAGS=-m64 FFLAGS=-m64 FCFLAGS=-m64 LDFLAGS=-m64 -L/usr/lib/sparcv9 -Wl,-rpath /usr/lib/sparcv9 --enable-f77 --enable-fc --enable-cxx --enable-romio --enable-debuginfo --enable-smpcoll --enable-threads=runtime --with-thread-package=posix --enable-shared tyr mpich-3.1.3-SunOS.sparc.64_gcc 110 tail log.make.SunOS.sparc.64_gcc CXX src/binding/cxx/initcxx.lo CXXLD lib/libmpicxx.la ld: fatal: file libmpicxx.so.12: open failed: No such file or directory ld: fatal: file processing errors. No output written to lib/.libs/libmpicxx.so.12.0.2 collect2: error: ld returned 1 exit status make[2]: *** [lib/libmpicxx.la] Error 1 make[2]: Leaving directory `/export2/src/mpich-3.1.3/mpich-3.1.3-SunOS.sparc.64_gcc' make[1]: *** [all-recursive] Error 1 make[1]: Leaving directory `/export2/src/mpich-3.1.3/mpich-3.1.3-SunOS.sparc.64_gcc' make: *** [all] Error 2 I get the same error which I reported for mpich-3.1.2, if I use "CFLAGS=-m64 -std=c11". I would be grateful, if somebody can fix the problem. Thank you very much for any help in advance. Kind regards Siegmar