Homebrew/homebrew — pull request #27541 by DennisOSRM (2014-03-14 09:59:48+00:00)
Title: [mercurial 2.9.1] fixes mercurial compile using Xcode5.1/clang3.4

Xcode 5.1 updates clang. There is a change in behavior how unknown compile options are handled. Mercurial emits a GCC specific flag that leads to a compile error. This patch restores previous behavior that the flag is to be ignored.