Using build step to trigger other jobs and wait could cause the dead lock.

Below presudo code of JobA:

pipeline
{
  stages
  {
    stage('test')
    {
       build job: "JobB", wait: true
    }
  }
} 

Here is the the example of use case problems:

• Let assume we have 2 executors
• JobA buildnumber#1 running (holding 1st executor) try trigger JobB.#1
• JobA buildnumber#2 also already running (holding 2nd executor) try trigger JobB.#2

The problem: we have a dead block. JobB.1 and JobB.2 are both wait for JobA.1 or JobA.2 finished for obtain executor(s). But JobA.1 and JobA.2 are waiting for JobB.1 and JobB.2 to finished.

Suggested solution: When a Job waiting for other jobs, it would be better to temporary release the executor, and obtain it back when it wait condition satisfy.