buildbot failure in on jmeter-nightly

[buildbot]

The Buildbot has detected a new failure on builder jmeter-nightly while 
building . Full details are available at:
    https://ci.apache.org/builders/jmeter-nightly/builds/1407

Buildbot URL: https://ci.apache.org/

Buildslave for this Build: bb_slave7_ubuntu

Build Reason: forced: by IRC user <fschumacher> on channel #asftest: use git 
revisions for nightly builds. one more try
Build Source Stamp: HEAD
Blamelist: 

BUILD FAILED: failed shell_4

Sincerely,
 -The Buildbot