APT Pinning fails when Default-Release set
	Part I. Miscellaneous subjects (and those still to be sorted)

APT Pinning fails when Default-Release set

Jurjen Bokma

February 2013

APT Pinning fails when the Default-Release is set in APT config. But without that setting, pinning can be used to give imported PPAs a lower priority.

We use apt-mirror to mirror many PPAs on our own server. Our customers are allowed to do package management, and should be able to install from these mirrors. But we do not want all of our PCs to recklessly install all of these PPA packages. So we de-prioritize these PPA packages by pinning them in /etc/apt/preferences.d/*.

The use of /etc/apt/preferences/* is somewhat documented. But it is important to also read Carlo Wood's errata and especially Roderick Schertler's “Using APT with more than 2 sources”.

Warning

	Warning
When I set `/etc/apt/apt.conf.d/80version` to: APT::Default-Release "precise"; then APT pinning fails to work! The pinning stops having any effect at all.

When I set /etc/apt/apt.conf.d/80version to:

APT::Default-Release "precise";

then APT pinning fails to work! The pinning stops having any effect at all.

Procedure 7. Down-prioritizing packages from PPAs

Figure out what PPAs are available

apprentice@pc:~$ls /var/lib/apt/lists/*_Release
Take a look at the Release file for the PPA you are targeting

apprentice@pc:~$ head -10 /var/lib/apt/lists/mirror.mydomain.com_ppa_mirror_ppa.launchpad.net_texlive-backports_ppa_ubuntu_dists_precise_Release Origin: LP-PPA-texlive-backports Label: TeX Live Backports PPA Suite: precise Version: 12.04 Codename: precise Date: Tue, 04 Dec 2012 19:43:57 UTC Architectures: amd64 armel armhf i386 powerpc Components: main Description: Ubuntu Precise 12.04 MD5Sum:
Note that Origin is LP-PPA-texlive-backports.
Reduce the priority of packages from this PPA
In /etc/apt/preferences.d/LP-PPA-texlive-backports_underpin.pref, put:
```
Package: *
Pin: release o=LP-PPA-texlive-backports
Pin-Priority: 400
	
```
and see the result of your work:
apprentice@pc:~$apt-cache policy texlive-science texlive-science: Installed: 2009-10ubuntu1 Candidate: 2009-10ubuntu1 Version table: 2012.20120611-1~ubuntu12.04.1 0 400 http://mirror.mydomain.com/ppa/mirror/ppa.launchpad.net/texlive-backports/ppa/ubuntu/ precise/main amd64 Packages *** 2009-10ubuntu1 0 500 http://osmirror.rug.nl/ubuntu/ precise/main amd64 Packages 100 /var/lib/dpkg/status
Installing not from the PPA

apprentice@pc:~$sudo apt-get install -s texlive-science
Installing from the PPA

apprentice@pc:~$ sudo apt-get install -s texlive-science -t o=LP-PPA-texlive-backports
```
	
```

	Note
One could also down-pin all other sources than Ubuntu/Canonical in a single file, like this: Package: * Pin-priority: 400 Package: * Pin: release o=Ubuntu Pin-priority: 900 Package: * Pin: release o=Canonical Pin-priority: 900

Note

One could also down-pin all other sources than Ubuntu/Canonical in a single file, like this:

Package: *
Pin-priority: 400

Package: *
Pin: release o=Ubuntu
Pin-priority: 900

Package: *
Pin: release o=Canonical
Pin-priority: 900


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