some tests failed:
failure: http://buildbot.rust-lang.org/builders/auto-mac-64-opt/builds/2946
exception: http://buildbot.rust-lang.org/builders/auto-mac-32-opt/builds/2952
exception: http://buildbot.rust-lang.org/builders/auto-mac-64-nopt-t/builds/2947
exception: http://buildbot.rust-lang.org/builders/auto-linux-32-opt/builds/2938
exception: http://buildbot.rust-lang.org/builders/auto-linux-32-nopt-t/builds/2937
exception: http://buildbot.rust-lang.org/builders/auto-linux-64-opt/builds/2940
exception: http://buildbot.rust-lang.org/builders/auto-linux-64-nopt-t/builds/2933
exception: http://buildbot.rust-lang.org/builders/auto-linux-64-x-android-t/builds/2930
exception: http://buildbot.rust-lang.org/builders/auto-win-32-opt/builds/2605
exception: http://buildbot.rust-lang.org/builders/auto-win-32-nopt-t/builds/2602
exception: http://buildbot.rust-lang.org/builders/auto-win-64-opt/builds/1441
exception: http://buildbot.rust-lang.org/builders/auto-win-64-nopt-t/builds/1432