Short version: The easiest way to do this is to configure your Open MPI installation with --disable-dlopen.
More detail: Open MPI uses a bunch of plugins for its functionality. When you dlopen libmpi in a private namespace (like Python does), and then libmpi tries to dlopen its plugins, the plugins can't find the symbols that they need in the main libmpi library (because they're in a private namespace). The workaround is to build Open MPI with all of its plugins slurped up into the libmpi library itself (i.e., so that Open MPI doesn't have to dlopen its plugins). > On Sep 17, 2015, at 11:08 AM, Joel Hermanns <joel.herma...@gmail.com> wrote: > > Hi all, > > I’m currently trying to use MPI within a Python extension (written in C++). I > was able to compile the extension and import it correctly, but as soon as I > run the function, which contains the MPI code, I get the following error: > > ``` > [aia256:15841] mca: base: component_find: unable to open > /pds/opt/openmpi-1.8.7/lib64/openmpi/mca_shmem_posix: > /pds/opt/openmpi-1.8.7/lib64/openmpi/mca_shmem_posix.so: undefined symbol: > opal_shmem_base_framework (ignored) > [aia256:15841] mca: base: component_find: unable to open > /pds/opt/openmpi-1.8.7/lib64/openmpi/mca_shmem_mmap: > /pds/opt/openmpi-1.8.7/lib64/openmpi/mca_shmem_mmap.so: undefined symbol: > opal_show_help (ignored) > [aia256:15841] mca: base: component_find: unable to open > /pds/opt/openmpi-1.8.7/lib64/openmpi/mca_shmem_sysv: > /pds/opt/openmpi-1.8.7/lib64/openmpi/mca_shmem_sysv.so: undefined symbol: > opal_show_help (ignored) > > ... > ``` > > (for the full message please have a look at [1]) > > > I put together a minimal example to reproduce this problem, which can be > found at [1]. Essentially, it is an extension that consist of only one > function. The function basically just runs MPI_Init and MPI_Finalize. > > Maybe someone has some ideas what I could try to do. > > Thanks in advance! > > > Best, > Joel > > > [1] https://github.com/jhedev/mpi_python > _______________________________________________ > users mailing list > us...@open-mpi.org > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/users > Link to this post: > http://www.open-mpi.org/community/lists/users/2015/09/27607.php -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
