mirage/mirage — pull request #337 by avsm (2014-12-10 11:19:22+00:00)
Title: Only activate MacOS X compilation by default on 10.10 (Yosemite)

Older revisions of MacOS X will use the generic Unix mode by default, since
the `vmnet` framework requires Yosemite or higher.

Reported by: Brian Brietzke