I would expect wait_on_lock to be the max time to wait, not how long between checks. That's what you would normally do in this situation, i.e. specify a max time to wait.

Yeah, we need a way to limit the time you're waiting for a lock, and the semantics of --wait-on-lock is a bit weird right now.

So, I changed things in d879cda:

• --wait-on-lock still works as before (0 (the default) implies no waiting (raise an error if lock is already there), a value implies enabling waiting with interval of specified number of seconds), but is deprecated;
• --wait-on-lock-limit can be used to i) enable waiting for lock to be released, ii) specify a maximum waiting time (if set to 0 is implies no waiting (raise error if lock is there), if set to -1 it implies waiting indefinitely);
• --wait-on-lock-interval can be used to specify the interval for re-checking whether the lock has been released (default 60 sec.)