This bug is a request to add dry-run option to beaker-expire-distros.

When the option is turned on, beaker-expire-distros prints the no-longer-accessible trees but does not update the DB.

In a lab where distro trees are removed in a batch and administrators run beaker-expire-distros manually once after the removal instead of cron job, the option is handy for the admins who would like to check the trees being expired without actually updating the DB.