Homebrew/homebrew — pull request #26492 by dpo (2014-02-07 05:13:09+00:00)
Title: Upgrade OpenMPI to 1.7.4.

Issues plaguing 1.7.3 appear to have been fixed. It's also possible to build against an external `libevent` so that there's no more duplication of the `libevent` header files.