Get upstream info in downstream Jenkins job

dowstream.job

node('myslave') {
    stage('downstream') {
       sh """
            export shortDescription="${getCauser()?.shortDescription}"
            export upstreamBuild="${getCauser()?.upstreamBuild}"
            export upstreamUrl="${getCauser()?.upstreamUrl}"
            export upstreamProject="${getCauser()?.upstreamProject}"
        """
    }
}

@NonCPS
def getCauser() {
  def upstream = currentBuild.rawBuild.getCause(hudson.model.Cause$UpstreamCause)
  return upstream
}