Gradle task to print all local branches that contain a commit when CI uses detached head strategy

build.gradle

task printCommitBranches(type: Exec) {
  executable "bash"
  args "-c", "git branch --contains HEAD"
  //store the output instead of printing to the console:
  standardOutput = new ByteArrayOutputStream()

  doLast {
      // split the output of the git command per newline and remove indentation whitespaces
      def outputLines = standardOutput.toString().split(/\r?\n\s+/)
      // if detached head, remove the line
      outputLines = outputLines.findAll({ it.contains("HEAD") == false })

      print outputLines.join(",")
  }
}