Race condition in FlowExecutionList

Resuming build at Tue Jan 03 10:37:18 UTC 2017 after Jenkins restart
Waiting to resume part of TestRun2 #2: Waiting for next available executor
Waiting to resume part of TestRun2 #2: Waiting for next available executor
Waiting to resume part of TestRun2 #2: Waiting for next available executor
Waiting to resume part of TestRun2 #2: Waiting for next available executor
Waiting to resume part of TestRun2 #2: Waiting for next available executor
Waiting to resume part of TestRun2 #2: Waiting for next available executor
Waiting to resume part of TestRun2 #2: Waiting for next available executor
...

node('XXXXX') {

  stage 'Stage 1'
    println 'Deploying to Stage 1...'

  stage 'Stage 2'
    println 'Running Tests in Stage 2'
    sleep 120
    println 'Tests passed!'

  stage 'Stage 3'
    println 'Deploying to Stage 3...'

}