Puppet 3.4.2 client hangs

[Forrie]

I'm experiencing an odd problem with one of my Puppet clients. These systems are identical in configuration, but this one hangs with:

puppet agent: applying configurat

and I see a yum process.

I checked that yum can operate on its own (it does) and there's no other process locking.   

There's nothing logged in /var/log/puppet (or messages).

I'm not sure what to make of it - the other two systems in this trio work fine.  This one is just stuck.   Could it be something in /var/lib/puppet that is messed up?

Thanks,

Forrest