I guess _get_packages_stored_locally would probably be a better name.  I could make tsk --> task.

As far as using exceptions, I guess that I could test for values first and log if they are not found.  Some people have recommended doing things this way: (EAFP vs. LBYL):  See: http://python.net/~goodger/projects/pycon/2007/idiomatic/handout.html#eafp-vs-lbyl