4.9.1. configure CLI option conventions

configure will, by default, search for header files and/or libraries for various optional features (e.g., various HPC network API/support libraries). If the relevant files are found, Open MPI will built support for that feature. If they are not found, Open MPI will skip building support for that feature.

However, if you specify --with-FOO (where FOO is the corresponding CLI option name for the feature) on the configure command line and Open MPI is unable to find relevant support for FOO, configure will assume that it was unable to provide a feature that was specifically requested, and will therefore abort so that a human can resolve out the issue.


Using --with-FOO to force Open MPI’s configure script to abort it if can’t find support for a given feature may be preferable to unexpectedly discovering at run-time that Open MPI is missing support for a critical feature.

Additionally, if a search directory is specified for FOO in the form --with-FOO=DIR, Open MPI will:

  1. Search for FOO’s header files in DIR/include.

  2. Search for FOO’s library files:

    1. If --with-FOO-libdir=LIBDIR was specified, search in LIBDIR.

    2. Otherwise, search in DIR/lib, and if they are not found there, search again in DIR/lib64.

  3. If both the relevant header files and libraries are found:

    1. Open MPI will build support for FOO.

    2. If the root path where the FOO libraries are found is neither /usr nor /usr/local, Open MPI will compile itself with RPATH flags pointing to the directory where FOO’s libraries are located.


      Open MPI does not RPATH /usr/lib[64] and /usr/local/lib[64] because many systems already search these directories for run-time libraries by default; adding RPATH for them could have unintended consequences for the search path ordering.


The --with-FOO-libdir=LIBDIR options are not usually needed; they are typically only needed when FOO’s libraries are installed in an “unexpected” location.

Also note the difference between --with-FOO=DIR and --with-FOO-libdir=LIBDIR: the former is a directory to which suffixes such as /include and /lib are added, whereas the latter is assumed to be a full library directory name (e.g., /opt/some_library/lib).