Bug#138721: acknowledged by developer (Re: Bug#138721: Pin entries in /etc/apt/preferences cause `apt-get dist-upgrade` to newly install seemingly totally unrelated packages)
Dear Jason,
I think we've got a misunderstanding here... (no offense!)
Jason Gunthorpe wrote:
> > apt-get wanted to install 9 *new*, (AFAICT) totally unrelated packages.
> > I checked the reverse dependencies of these 9 packages, and the
> > forward dependencies of the held-back and to-be-upgraded packages,
> > but nothing pointed at any one of the 9 to-be-newly-installed packages!
>
> Use the -o debug::pkgproblemresolver=true option which will help you
> determine why those packages were selected. Something on your system does
> depend on them somehow or they would never have been selected.
That's what I thought, too. But why would apt-get try to install these 9 packages (lib*, see below) *only as long* as
/etc/apt/preferences contained the three "Pin" entries?
I did *not* let apt-get install the 9 packages before removing the "Pin"s (and neither thereafter)! Nevertheless, apt-get *stopped*
begging for these packages to be installed as soon as I removed the "Pin"s!
For debugging purposes, I downgraded my "apache", "apache-common", "apache-doc", and "libapache-mod-ssl" pkgs to their prior
versions, and restored the "Pin" entries in /e/a/p. This is the `apt-get -o debug::... -u dist-upgrade` transcript:
| io:~> apt-get -u -o debug::pkgproblemresolver=true dist-upgrade
| Reading Package Lists... Done
| Building Dependency Tree... Done
| Calculating Upgrade... Starting
| Starting 2
| Investigating libapache-mod-perl
| Package libapache-mod-perl has broken dep on apache-common
| Considering apache-common 13 as a solution to libapache-mod-perl 3
| Holding Back libapache-mod-perl rather than change apache-common
| Investigating apache-perl
| Package apache-perl has broken dep on apache-common
| Considering apache-common 13 as a solution to apache-perl -1
| Holding Back apache-perl rather than change apache-common
| Investigating libapache-mod-ssl
| Package libapache-mod-ssl has broken dep on apache
| Considering apache 1 as a solution to libapache-mod-ssl 0
| Holding Back libapache-mod-ssl rather than change apache
| Package libapache-mod-ssl has broken dep on apache-perl
| Considering apache-perl -1 as a solution to libapache-mod-ssl 0
| Holding Back libapache-mod-ssl rather than change apache-perl
| Or group keep for libapache-mod-ssl
| Try to Re-Instate libapache-mod-ssl
| Done
| Done
| The following NEW packages will be installed:
| libdevel-symdump-perl libdigest-md5-perl libhtml-parser-perl
| libhtml-tagset-perl libhtml-tree-perl libmime-base64-perl
| libnet-perl liburi-perl libwww-perl
| The following packages have been kept back
| libapache-mod-ssl
| 0 packages upgraded, 9 newly installed, 0 to remove and 1 not
| upgraded.
| Need to get 824kB of archives. After unpacking 2798kB will be used.
| Do you want to continue? [Y/n] n
| Abort.
At least, that would explain why apt-get wants to install the 9 Perl-related lib pkgs, because "apache-perl" depends on
"libapache-mod-perl" which depends on these.
But then again, why on earth is apt-get "investigating" the "libapache-mod-perl" and "apache-perl" pkgs, which I don't have
installed at all?
| io:~> dpkg -l apache-perl libapache-mod-perl
| Desired=Unknown/Install/Remove/Purge/Hold
| | Status=Not/Installed/Config-files/Unpacked/Failed-config/Half-installed
| |/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uc=bad)
| ||/ Name Version Description
| +++-=========================-=========================-=================
| pn apache-perl <none> (n/a)
| pn libapache-mod-perl <none> (n/a)
Julian.
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