ERROR: Error fetching remote repo 'origin'
hudson.plugins.git.GitException: Failed to fetch from git@url.com:reponame
...
... returned status code 1:
...
error: cannot lock ref `refs/remote/origin/feature_A': Unable to create '/jenkinsurl/workspace/jobname@3/.git/refs/remotes/origin/feature_A.lock': File exists.

Another git process seems to be running in this repository...

#!/usr/bin/env groovy

def items_to_be_tested

pipeline {

  agent none

  options {
    disableConcurrentBuilds()
    timestamps()
    buildDiscarder logRotator(numToKeepStr: '20')
    allowBrokenBuildClaiming()
    ansiColor('xterm')
  }

  stages {
    stage ( "Run on items from CMake" ) {
      stages {
        stage ( "Get list of items from CMake" ) {
          agent any
          steps {
            dir ( "${WORKSPACE}/items" ) {
              script { items_to_be_tested = getItemToBeTested() }
            }
          }
          post { cleanup { deleteDir() } }
        }
        stage ("Run TOOL on items from CMake") {
          steps {
            script { parallel generateTaskMap(items_to_be_tested) }
          }
        }
      }
    }
  } // stages
}

def getItemToBeTested() {
  return params.ITEMS.tokenize(" ;,:").join(";")
}

def getTaskBody(item) {
  return {
    // Grab lock to limit parallel tasks to MAX (~8)
    lock( label: 'TOOL_lock', quantity: 1) {
      stage("${item}") {
        node('lsf') {

          checkout(scm)

          // Run tests here
          sleep 1200  // running TOOL takes roughly 20 minutes

          // post directive is not supported here, please do clean up after you are done
          deleteDir()
        }
      }
    }
  }
}


def generateTaskMap(item_list) {
  stages = [:]
  expanded_item_list = item_list.split(';') as List
  echo "Item list: ${expanded_item_list}"
  expanded_item_list.each {
    echo "Adding tests for ${it}"
    stages["TOOL on ${it}"] = getTaskBody(it)
  }
  return stages
}