This is similar to PUP-4442, as it is also about issues with checking errors of an Dir.mkdir.
Puppet correctly surfaces this error now, so I'm going to close this ticket. The other ticket 4442 is still an issue so I'll leave that open.
$ puppet apply -e ''
...
Notice: Compiled catalog for localhost in environment production in 0.01 seconds
Notice: /Stage[main]/Main/Notify[hi]/message: defined 'message' as 'hi'
Error: Failed to apply catalog: No space left on device - Out of disk space
Error: Could not save last run local report: No space left on device - Out of disk space
Error: Could not send report: No space left on device - Out of disk space