Caused by: hudson.plugins.git.GitException: Error performing command: git tag -a -f -m Jenkins Build #8 jenkins-regress-8
Command "git tag -a -f -m Jenkins Build #8 jenkins-regress-8" returned status code 128: 
*** Please tell me who you are.

Run

  git config --global user.email "you@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.