some tests failed:
failure: http://buildbot.rust-lang.org/builders/auto-win-32-nopt-t/builds/2611
exception: http://buildbot.rust-lang.org/builders/auto-mac-32-opt/builds/2961
exception: http://buildbot.rust-lang.org/builders/auto-mac-64-opt/builds/2955
exception: http://buildbot.rust-lang.org/builders/auto-mac-64-nopt-t/builds/2956
exception: http://buildbot.rust-lang.org/builders/auto-linux-32-opt/builds/2947
exception: http://buildbot.rust-lang.org/builders/auto-linux-32-nopt-t/builds/2946
exception: http://buildbot.rust-lang.org/builders/auto-linux-64-opt/builds/2949
exception: http://buildbot.rust-lang.org/builders/auto-linux-64-nopt-t/builds/2942
exception: http://buildbot.rust-lang.org/builders/auto-linux-64-x-android-t/builds/2939
exception: http://buildbot.rust-lang.org/builders/auto-win-32-opt/builds/2614
exception: http://buildbot.rust-lang.org/builders/auto-win-64-opt/builds/1450
exception: http://buildbot.rust-lang.org/builders/auto-win-64-nopt-t/builds/1441