startscheduler fails to start scheduler process, warns "The scheduler worker is already running"

[chrisinmtown]

Using CakePHP v2.10.22 and PHP Resque Version 4.1.2. I use this command to start the scheduler:

cake CakeResque.CakeResque startscheduler --interval 5

But it fails to start the expected process. The output is:

Creating the scheduler workers
The scheduler worker is already running

There's probably an error between the keyboard and the chair here, but I'm a bit puzzled. I wonder if this command simply declines to start a new one because it has detected a running scheduler? But I cannot find a scheduler in the process table. Why/how does it detect a running scheduler?

[wa0x6e]

Check that there's no leftover pid file, due to previous incorrect shutdown.

[chrisinmtown]

Where is a PID file? In our case this seems to rely on ResqueStatus which caches data in Redis. Yes I agree that there was a previous incorrect shutdown, but the start scheduler should be robust to a machine losing power or other unexpected crash that may leave junk on the filesystem.