Liip\RMT\VCS\VCSInterface::getAllModificationsSince PHP Method

    public function getAllModificationsSince($tag, $color = true, $noMergeCommits = false);

 /**
  * Gets hash of latest commit
  *
  * @return string
  */
 private function getCurrentCommitHash()
 {
     $colorOutput = false;
     $modifications = $this->vcs->getAllModificationsSince('HEAD~1', $colorOutput);
     $lastModification = reset($modifications);
     return substr($lastModification, 0, strpos($lastModification, ' '));
 }