Something I proposed a while back: A workable backtracking mechanism in apt.
There already is for single "off-site" packages--an option to explicitely enable a "downgrade" back to the original. Simplest would be the backtrack to the previous systems configuration. Snapshots would be a larger and more complex solution. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]