I changed mirror.anl.gov to mirror.mcs.anl.gov and the dist upgrade was able to proceed.
However, it did add an archive.ubuntu.com line at the end of my sources.list. -- A unresolvable problem occurred while calculating the upgrade. https://launchpad.net/bugs/92096 -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
