12.4. Running autogen.pl

You can now run OMPI’s top-level autogen.pl script. This script will invoke the GNU Autoconf, Automake, and Libtool commands in the proper order and do a bunch of component discovery and housekeeping to setup to run OMPI’s top-level configure script.

Running autogen.pl may take a few minutes, depending on your system. It’s not very exciting to watch.

If you have a multi-processor system, enabling the multi-threaded behavior in Automake 1.11 (or newer) can result in autogen.pl running faster. Do this by setting the AUTOMAKE_JOBS environment variable to the number of processors (threads) that you want it to use before invoking autogen.pl. For example (you can put this in your shell startup files):

# For bash/sh/zsh:

# For csh/tcsh:


You generally need to run autogen.pl whenever the top-level file configure.ac changes, or any files in the config/ or <project>/config/ directories change (these directories are where a lot of “include” files for Open MPI’s configure script live).


You do NOT need to re-run autogen.pl if you modify a Makefile.am.