apt-get will fail in case of any missing dependencies The most common cause of this was when a package had a soname bump , although this is actually fixed, but it makes a nice example.
If you consider the gnome3-team/gnome3-staging ppa for 16.04, the mutter library package is: libmutter0h however on stock 16.04 it is: libmutter0g Now when we run ppa-purge, libmutter0h will get selected to remove, however (the downgraded) gnome-shell,gdm etc will depend on libmutter0g, so apt-get will refuse to install these packages, since libmutter0g is not selected for installation. Another example (which is NOT fixed) would be if a package was renamed for some reason. Say package 'foo' was renamed to package 'bar' on a ppa, 'bar' would have a replaces field in the control to facilitate the upgrade, but ppa-purge doesnt know how to roll that back. So package 'bar' get removed and any package that depends on 'foo' will fail to install. It may be possible to use apt-get upgrade or apt-get dist- upgrade to help with these but I have never tried that. These generally only affect the more complex ppa's like gnome3-staging and xorg-edgers, and in fact they are probably the two best test-cases for seeing if things work. aptitude is unpredictable, although it allows the user to proceed, its attempts to resolve the dependencies are not always correct and it will also quite happily remove packages that shouldnt be. Having apt-get working 100% of the time would be better -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1408031 Title: Requesting purge to abort fails. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ppa-purge/+bug/1408031/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
