Build failed in Jenkins: Cassandra #1625

[Apache Jenkins Server]

See <https://builds.apache.org/job/Cassandra/1625/>

------------------------------------------
Started by an SCM change
Building remotely on ubuntu4 in workspace 
<https://builds.apache.org/job/Cassandra/ws/>
Checkout:Cassandra / <https://builds.apache.org/job/Cassandra/ws/> - 
hudson.remoting.Channel@706d810e:ubuntu4
Using strategy: Default
Last Built Revision: Revision 3eff5455dc58e6b7e0aadf987a635320f4bd5ef1 
(origin/trunk)
Fetching changes from 1 remote Git repository
Fetching upstream changes from 
https://git-wip-us.apache.org/repos/asf/cassandra.git
Commencing build of Revision 6d5d91eece057e18812210cdd12dcce2ac2a25ae 
(origin/trunk)
Checking out Revision 6d5d91eece057e18812210cdd12dcce2ac2a25ae (origin/trunk)
FATAL: Could not apply tag jenkins-Cassandra-1625
hudson.plugins.git.GitException: Could not apply tag jenkins-Cassandra-1625
        at hudson.plugins.git.GitAPI.tag(GitAPI.java:737)
        at hudson.plugins.git.GitSCM$4.invoke(GitSCM.java:1320)
        at hudson.plugins.git.GitSCM$4.invoke(GitSCM.java:1268)
        at hudson.FilePath$FileCallableWrapper.call(FilePath.java:2180)
        at hudson.remoting.UserRequest.perform(UserRequest.java:118)
        at hudson.remoting.UserRequest.perform(UserRequest.java:48)
        at hudson.remoting.Request$2.run(Request.java:287)
        at 
hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:72)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
        at java.util.concurrent.FutureTask.run(FutureTask.java:166)
        at 
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
        at 
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
        at java.lang.Thread.run(Thread.java:636)
Caused by: hudson.plugins.git.GitException: Command "git tag -a -f -m Jenkins 
Build #1625 jenkins-Cassandra-1625" returned status code 128:
stdout: 
stderr: 
*** Please tell me who you are.

Run

  git config --global user.email "y...@example.com"
  git config --global user.name "Your Name"

to set your account's default identity.
Omit --global to set the identity only in this repository.

fatal: empty ident  <jenk...@janus.apache.org
> not allowed

        at hudson.plugins.git.GitAPI.launchCommandIn(GitAPI.java:786)
        at hudson.plugins.git.GitAPI.launchCommand(GitAPI.java:748)
        at hudson.plugins.git.GitAPI.launchCommand(GitAPI.java:758)
        at hudson.plugins.git.GitAPI.tag(GitAPI.java:735)
        ... 12 more