some tests failed:
failure: http://buildbot.rust-lang.org/builders/auto-mac-64-nopt-t/builds/2961
exception: http://buildbot.rust-lang.org/builders/auto-mac-32-opt/builds/2966
exception: http://buildbot.rust-lang.org/builders/auto-mac-64-opt/builds/2960
exception: http://buildbot.rust-lang.org/builders/auto-linux-32-opt/builds/2952
exception: http://buildbot.rust-lang.org/builders/auto-linux-32-nopt-t/builds/2951
exception: http://buildbot.rust-lang.org/builders/auto-linux-64-opt/builds/2954
exception: http://buildbot.rust-lang.org/builders/auto-linux-64-nopt-t/builds/2947
exception: http://buildbot.rust-lang.org/builders/auto-linux-64-x-android-t/builds/2944
exception: http://buildbot.rust-lang.org/builders/auto-win-32-opt/builds/2619
exception: http://buildbot.rust-lang.org/builders/auto-win-32-nopt-t/builds/2616
exception: http://buildbot.rust-lang.org/builders/auto-win-64-opt/builds/1455
exception: http://buildbot.rust-lang.org/builders/auto-win-64-nopt-t/builds/1446