We have multiple jobs (A B C) that trigger that all trigger the same job ( D ) as post build "Build Steps"
What we see is that each of A,B or C would randomly hang on "Waiting for the completion of D" despite the fact that the D instance they called has completed long time ago (we're talking jobs hanging for days sometimes)
The only thing we saw in JVM monitoring that was weird was things like one instance of A waiting for another instance of A with "waiting for Check point COMPLETED on A#XYZ)
All the jobs in question have concurrent execution enabled.
Unfortunately we're unable to provide an exact scenario in which the hang happens as it appears random and happens on some days but not others.
Let me know if there is something in Jenkins logs i should look for to provide more debug info.
This issue is critical for us, since we need to execute post-build events in a blocking manner and it seems this plugin is the only one giving us this ability.