When a build is not able to acquire a lock, the only way to know what build is holding the lock is to go to the Lockable Resources manager screen. Also there could be several builds in the queue waiting in front of that build.

The console out put only provides information about the fact that the resources are not available:

Trying to acquire lock on [<resourceName>]
Found 0 available resource(s). Waiting for correct amount: 1.
[<resourceName>] is locked, waiting...

It would be great if the console output could provide information about what build(s) we are waiting for and/or how many builds we are waiting for.