Homebrew/homebrew — pull request #31601 by Ventero (2014-08-14 17:44:32+00:00)
Title: mercury: Don't enable the .NET backend when building with mono.

The .NET IL backend [is unsupported](http://www.mercurylang.org/dotnet.html) and does not build.

See also https://github.com/Homebrew/homebrew/pull/31552#issuecomment-52041226.