[Linux-bruxelles] apt-pinning: apt mix-and-match between Stable, Testing, and Unstable sources

[Ald0]

Bonjour la ml,

un ami m'a posté ce matin une doc un peu mystérieuse mais intéressante, où il 
y est expliqué qu'il est possible de mélanger stable, unstable et testing 
pour ce qui est des sources dans notre Debian; je cherche toujours à 
rapatrier et mettre à jour uniquement alsa-base et alsa-utils vu que j'ai tj 
pas de son à niveau(/volume) potable/acceptable sur un EEPC:
je voudrais juste savoir si la méthode ci-dessous est trop élaborée si mon
but n'est que de mettre à jour als-base + alsa-utils ?

Dans les exemples je ne comprens pas pourquoi "il" utilise * et pas
d'exemple de maj de seulement qqs packages !

Aldo.


=== <snip> ===

Apt-Pinning for Beginners

Why apt-pinning?

Do you run Debian? Have you ever gotten annoyed at how Debian Stable always
seems to be out of date?

I will show you a way that you can have apt mix-and-match between Stable,
Testing, and Unstable sources. This will allow you to run a mostly-Stable
system, but also track the latest and greatest of those packages that you are
most keenly interested in.

Why do this? Stable is covered by the Security Team. Testing and Unstable are
not. For non-critical services, like perhaps your mailer, or your window
manager, this is not so important, and the newest versions may have additional
features that are desired. It is these packages that are perfect for pinning to
a version, other than Stable.

sources.list

The first step is to set up your /etc/apt/sources.list to include your typical
Stable, plus the Testing/Unstable sources that you want.

A simple sources.list may look like this:

#Stable
deb http://ftp.us.debian.org/debian stable main non-free contrib
deb http://non-us.debian.org/debian-non-US stable/non-US main contrib non-free

#Testing
deb http://ftp.us.debian.org/debian testing main non-free contrib
deb http://non-us.debian.org/debian-non-US testing/non-US main contrib non-free

#Unstable
deb http://ftp.us.debian.org/debian unstable main non-free contrib
deb http://non-us.debian.org/debian-non-US unstable/non-US main contrib non-free
You would probably want to add your mirrors, security.debian.org, and perhaps
the appropriate deb-src lines. Here is a copy of my actual sources.list.

preferences

The next step is to create/edit your /etc/apt/preferences file. preferences is
where the apt-pinning takes place. Normally, the highest version of an
available package wins, but we will override that.

A simple preferences file may look like this:

Package: *
Pin: release a=stable
Pin-Priority: 700

Package: *
Pin: release a=testing
Pin-Priority: 650

Package: *
Pin: release a=unstable
Pin-Priority: 600
Note the decending values. Since Stable has the highest pin-priority, it will
be installed preferentially over Testing or Unstable.

My actual preferences file is what you see above.

apt-get update

Now we are ready to apt-get update. This will add the new repositories to apt's
list.

E: Dynamic MMap ran out of room

You may find that you receive an error like the following:

E: Dynamic MMap ran out of room
E: Error occured while processing sqlrelay-sqlite (NewPackage)
E: Problem with MergeList
/var/lib/apt/lists/ftp.us.debian.org_debian_dists_woody_contrib_binary-i386_Packages
E: The package lists or status file could not be parsed or opened.
This is caused because apt's cache is too small to handle all of the packages
that are included with stable, testing, and unstable. This is also very easy to
fix. Add the following line to /etc/apt/apt.conf

APT::Cache-Limit "8388608";
Thanks to R (Chandra) Chandras for pointing out this problem

Installing new packages

To install a new package, it is just as it ever was, apt-get install <package>.
If the package exists in Stable, then that is what it will grab. If the package
exists only in Unstable, then from Unstable it will be gotten.

What if the package exists in both Stable and Unstable, but we want the
Unstable version? There are two ways we can do that, each with a slightly
different syntax, and each with a slightly different effect.

apt-get install <package>/unstable
This will install the unstable version of the package, and try to meet any
dependencies from Stable. This may not work, but it will tell you why:

# apt-get install zsh/unstable
Reading Package Lists... Done
Building Dependency Tree... Done
Selected version 4.0.6-7 (Debian:unstable) for zsh
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.

Since you only requested a single operation it is extremely likely that
the package is simply not installable and a bug report against
that package should be filed.
The following information may help to resolve the situation:

Sorry, but the following packages have unmet dependencies:
  zsh: Depends: libc6 (>= 2.2.5-13) but 2.2.5-11.1 is to be installed
E: Sorry, broken packages
apt-get -t unstable install <package>
This will install the Unstable version of the package, and try to meet any
dependencies from Unstable. This may produce better results.

# apt-get -t unstable install zsh
Reading Package Lists... Done
Building Dependency Tree... Done
The following extra packages will be installed:
  libc6 libc6-dev libc6-pic libdb1-compat locales
The following NEW packages will be installed:
  libdb1-compat
5 packages upgraded, 1 newly installed, 0 to remove and 394  not upgraded.
Need to get 11.6MB of archives. After unpacking 606kB will be used.
Do you want to continue? [Y/n]
That's it!

Armed with a complete sources.list and a minimal preferences, you can go ahead
and mix-and-match between the various Debian releases.

Have fun!

http://jaqque.sbih.org/kplug/apt-pinning.html

=== </snip> ===