12.3. Compiler Pickyness by Default

If you are building Open MPI from a Git clone (i.e., there is a .git directory in your build tree), the default build includes extra compiler pickyness, which will result in more compiler warnings than in non-developer builds. Getting these extra compiler warnings is helpful to Open MPI developers in making the code base as clean as possible.

Developers can disable this picky-by-default behavior by using the --disable-picky configure option. Also note that extra-picky compiles do not happen automatically when you do a VPATH build (e.g., if .git is in your source tree, but not in your build tree).

Prior versions of Open MPI would automatically activate a lot of (performance-reducing) debugging code by default if .git was found in your build tree. This is no longer true. You can manually enable these (performance-reducing) debugging features in the Open MPI code base with these configure options:

  • --enable-debug

  • --enable-mem-debug

  • --enable-mem-profile


These options are really only relevant to those who are developing Open MPI itself. They are not generally helpful for debugging general MPI applications.