buildbot failure in kvm on x86_64

The Buildbot has detected a new failure on builder x86_64 while building kvm. Full details are available at:
http://buildbot.b1-systems.de/kvm/builders/x86_64/builds/835

Buildbot URL: http://buildbot.b1-systems.de/kvm/

Buildslave for this Build: b1_kvm_1

Build Reason: The Nightly scheduler named 'nightly_master' triggered this build Build Source Stamp: [branch master] HEAD
Blamelist:

BUILD FAILED: failed git

sincerely,
-The Buildbot