[git] Jenkins Git Plugin: How to build specific tag?

If you are using Jenkins pipelines and want to checkout a specific tag (eg: a TAG parameter of your build), here is what you can do:

stage('Checkout') {
  steps {
    checkout scm: [$class: 'GitSCM', userRemoteConfigs: [[url: 'YOUR_GIT_REPO_URL.git', credentialsId: 'YOUR_GIT_CREDENTIALS_ID' ]], branches: [[name: 'refs/tags/${TAG}']]], poll: false
  }
}