SCM initiated builds with scripted/imperative pipeline

[Gardell, Steven]

I am trying to get parallel builds to run as described in several different places including:

 

https://www.cloudbees.com/blog/parallelism-and-distributed-builds-jenkins

https://jenkins.io/blog/2016/10/16/stage-lock-milestone/

 

What I find is that this mechanism (basically “lock(…) { milestone() { do-build }}”) works at the scripting level when I invoke the build manually but not for SCM (in my case Perforce) initiated builds. This is true with both ‘SCM polling’ and ‘Perforce triggered’ builds. It seems that this SCM initiation simply doesn’t run if the job is currently running. This same build is being triggered by SCM polling when it is not currently running, so I am by that minor challenge.

Any suggestions?