It looks like MPICH could not find weak symbol support for some reason. From your log at https://people.freebsd.org/~yuri/mpich-configure.log checking for type of weak symbol alias support... no checking whether __attribute__ ((weak)) allowed... yes checking whether __attribute__ ((weak_import)) allowed... yes checking whether __attribute__((weak,alias(...))) allowed... yes The expected output should be checking for type of weak symbol alias support... pragma weak I need to build MPICH on the same FreeBSD version to figure it out. Min On 2018/09/27 22:16, Yuri wrote: On 9/27/18 7:48 PM, Si, Min wrote: Could you please attache the whole config.log ? I just tried MPICH-3.2.1 on FreeBSD 10.3, it lists both PMPI and MPI symbols. It looks like your build does not contain weak symbols. FreeBSD 10.3 is old, about to become obsolete. Here is the complete configure.log: https://people.freebsd.org/~yuri/mpich-configure.log Yuri _______________________________________________ discuss mailing list [email protected]<mailto:[email protected]> To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss