Re: Backup package and dpkg (was Re: dpkg-disappear-replace.txt)
moth@magenta.com said:
> Bill Mitchell:
> > dpkg --install textutils.deb
> > dpkg --install --force-conflicts elv-fmt.deb
> > dpkg --install textutils.deb
> ...
> Ok, but I still don't understand. What would be different if you had
> installed textutils.deb only the second time?
This morning, I took a second look at what I'd said last night in
this and my other few examples, and saw that my quick examples had
been too quick (there was even an obvious cut&paste error in one).
However, there is a difference in this particular instance. The file
/usr/doc/copyright/elvis, installed by elv-fmt, will still be in place.
Making /usr/doc/copyright a special case doesn't solve the general
problem here. The elv-fmt package might have installed /usr/bin/foo
as well, and that file not have been overwritten by subsequent upgrade
of textutils -- the same general case.
> The reason behind a file from one package being overwritten by that
> same file from another package is immaterial. The point is that it
> can happen.
>
> My point is, if there is an interface to identify the files which may
> have ambiguously originated from one of several packages, it's a
> simple matter to explicitly back up these files so that it doesn't
> really matter what order dpkg installs the packages.
Seems so, though I'm not sure how simple it'd be to identify those
files and be sure to get it right.
Another case would be the installation of textutils, followed by the
installation and subsequent removal of elv-fmt. This leaves
/usr/bin/fmt and /usr/man/man1/fmt missing. Is it necessary to
note this information when backing up the system, and get such
files removed when restoring it?
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