Please help me understand APT pinning...

[Michael Goetze <mgoetze@mgoetze.net>]

Hi,

I've struggled with this issue for hours and gotten no help from 
Manpages, nor IRC. So if someone could help me and CC me on their reply 
(as I am not subscribed), I would be very grateful.

I am running a Debian Squeeze system. I want to install selected 
packages from debian-multimedia and grml on it. Furthermore, I don't 
trust Opera Software ASA completely, and therefore want to make sure no 
packages of theirs are installed over packages available from anywhere 
else. As a secondary goal, I want to use my ISP's mirror whereever 
possible, to avoid unnecessary internet traffic. Allow me to post my 
attempts to configure this:

=== Begin /etc/apt/sources.list ===
deb http://mirror.netcologne.de/debian squeeze main contrib non-free
deb http://mirror.netcologne.de/debian sid main
deb http://deb.opera.com/opera/ squeeze non-free
deb http://mirror.netcologne.de/debian-multimedia.org squeeze main
deb http://mirror.netcologne.de/www.grml.org/deb.grml.org/ grml-testing main
=== End /etc/apt/sources.list ===
=== Begin /etc/apt/preferences ===
Package: *
Pin: release o=The grml project
Pin-Priority: 400

Package: *
Pin: release o=Unofficial Multimedia Packages
Pin-Priority: 400

Package: *
Pin: origin deb.opera.com
Pin-Priority: 300
=== End /etc/apt/preferences ===
=== Begin output of apt-cache policy ===
Package files:
 100 /var/lib/dpkg/status
     release a=now
 400 http://mirror.netcologne.de grml-testing/main Packages
     release o=The grml project,a=grml-testing,n=grml-testing,l=grml,c=main
     origin mirror.netcologne.de
 500 http://mirror.netcologne.de squeeze/main Translation-en_US
 990 http://mirror.netcologne.de squeeze/main Packages
     release v=None,o=Unofficial Multimedia 
Packages,a=testing,n=squeeze,l=Unofficial Multimedia Packages,c=main
     origin mirror.netcologne.de
 990 http://deb.opera.com squeeze/non-free Packages
     release o=Opera Software ASA,a=testing,n=squeeze,l=The Opera web 
browser,c=non-free
     origin deb.opera.com
 500 http://mirror.netcologne.de sid/main Packages
     release o=Debian,a=unstable,n=sid,l=Debian,c=main
     origin mirror.netcologne.de
 990 http://mirror.netcologne.de squeeze/non-free Packages
     release o=Debian,a=testing,n=squeeze,l=Debian,c=non-free
     origin mirror.netcologne.de
 990 http://mirror.netcologne.de squeeze/contrib Packages
     release o=Debian,a=testing,n=squeeze,l=Debian,c=contrib
     origin mirror.netcologne.de
 990 http://mirror.netcologne.de squeeze/main Packages
     release o=Debian,a=testing,n=squeeze,l=Debian,c=main
     origin mirror.netcologne.de
Pinned packages:
=== End output of apt-cache policy ===

As you can see, I failed miserably. The very same method that works fine 
for the grml packages, fails for the debian-multimedia packages. I have 
also tried "l=" instead of "o=", as well as copy&pasting the complete 
release line from the output of apt-cache policy. I have tried using 
double quote characters. I have tried changing the order of grml and 
debian-multimedia in the preferences file. I have run aptitude update or 
apt-get update after every change. Nothing works.

For Opera, I have not invested quite as much effort, especially since I 
specifically want the "origin" feature, not the "release" feature, to 
work here; however, "release o=Opera Software ASA" also does not work, 
nor does adding double-quotes around "deb.opera.com".

So if anyone understands APT pinning... please help me!

Regards,
Michael

PS Again, please CC me, I am not subscribed to this list.