On 2012-01-05 16:38:04 +0000, Darac Marjal wrote: > On Thu, Jan 05, 2012 at 03:43:22PM +0100, Vincent Lefevre wrote: > > For Debian/unstable: > > > > Does there exist a utility to downgrade a package with its > > dependencies and reverse-dependencies? The old packages would > > be taken from /var/cache/apt/archives, and the tool should be > > able to find automatically which packages/versions are needed > > to satisfy all the dependencies (with minimum change) and > > should be able to handle virtual packages. > > Typically there isn't. > > The big problem with rolling back packages is the maintainer scripts > (post-install, pre-remove etc). These are generally written in such a > way as to facilitate UPgrades.
I know, but I assumed that here, there weren't such problems (this was more or less Xorg downgrades to detect when a bug appeared, and this consists mostly of libraries and drivers, so that the maintainer scripts probably do almost nothing). > I was in this situation myself a while ago and decided that the best > solution was as follows: > * Before upgrading, take an LVM snapshot (this, of course, assumes > you ARE on LVM). > * Perform the package upgrade and then test the new version. > * If happy, delete the snapshot (this is a cheap operation) > * If unhappy, rollback the snapshot (which takes a bit of time, but > gets you back to where you were). The problem here is that I didn't find the bug immediately. Fortunately I commit the "dpkg -l" output to my personal SVN repository from time to time. So, this helped a bit: I grepped xserver related packages, and wrote a script to convert the output to a list of .deb files. However I had to do various manual corrections. I had to go back to the 2010-10-10 version to make the bug disappear. -- Vincent Lefèvre <vinc...@vinc17.net> - Web: <http://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <http://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / Arénaire project (LIP, ENS-Lyon) -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20120106014433.ga27...@xvii.vinc17.org
