Has anyone ever gotten "cobbler reposync" to work under CentOS 7.3?

I've imported the major Ubuntu distributions, 12, 14, and 16, but I can't get cobbler to successfully mirror the Ubuntu repo.

I get "waiting for /var/www/cobbler/repo_mirror/Ubuntu-12.04.2-x86_64 lock since 20 seconds at /usr/share/perl5/vendor_perl/LockFile/Simple.pm line 206." a few times until it times out and crashes.

Has anyone seen this before?