pinning negative preferences not preventing installation

[Matt LaPlante]

Binary package hint: apt

I'm not sure if this is a problem with the documentation, or a problem with the application, however apt is not behaving as expected when pinning negative values.

According to man 5 apt_preferences, a Pin-Priority "P < 0 prevents the version from being installed."

Now I'll take a package at random and pin it in /etc/apt/preferences:
Package: python-tcm
Pin: version 0.5.1-0ubuntu4
Pin-Priority: -100

And yet, the package attempts to install:

root@prizm:/tmp# apt-get -Vs install python-tcm
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
   pessulus (2.16.3-0ubuntu1)
   python-tcm (0.5.1-0ubuntu4)
0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded.
Inst python-tcm (0.5.1-0ubuntu4 Ubuntu:7.10/gutsy)
Conf python-tcm (0.5.1-0ubuntu4 Ubuntu:7.10/gutsy)

The same occurs with a generalized version (Pin: version *).

[Jisakiel (jisakiel)]

I found a similar problem and I was going to report it here also; it wasn't working with "release a=unstable" and pins for debian repositories...

Finally I found the debian mirror I was using was missing the Release files in /var/lib/apt/lists and therefore the release wasn't being applied; does not seem to be your case, but I'd double check there, and perhaps would try as well changing mirrors, just in case...

[Mumia W. (mumia-w-18)]

I also have this problem with apt 0.7.9ubuntu17 on Ubuntu Hardy Heron. Pinning does not work as documented in "man apt_preferences"; I don't want to install a buggy/vulnerable version of libimlib2, so I pinned it this way:

---file:/etc/apt/preferences---
Package: libimlib2
Pin: version 1.4.0-1ubuntu1
Pin-Priority: -10
-------------end---------------

However, this failed to have any effect on the package's priority:

----------------------
$ apt-cache policy libimlib2
libimlib2:
  Installed: (none)
  Candidate: 1.4.0-1ubuntu1
  Package pin: 1.4.0-1ubuntu1
  Version table:
     1.4.0-1ubuntu1 -10
        500 http://us.archive.ubuntu.com hardy/main Packages
----------------------

In previous versions of apt, the changed priority (-10) would be listed where the 500 is listed in the above output. Attempts to install a package requiring that library may well bring in the buggy library:

-------------------------------------
:$ sudo apt-get -s install pypanel
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
  libid3tag0 libimlib2 python-xlib
The following NEW packages will be installed:
  libid3tag0 libimlib2 pypanel python-xlib
0 upgraded, 4 newly installed, 0 to remove and 8 not upgraded.
Inst libid3tag0 (0.15.1b-10 Ubuntu:8.04/hardy)
Inst libimlib2 (1.4.0-1ubuntu1 Ubuntu:8.04/hardy)
Inst python-xlib (0.14-1 Ubuntu:8.04/hardy)
Inst pypanel (2.4-1.1build1 Ubuntu:8.04/hardy)
Conf libid3tag0 (0.15.1b-10 Ubuntu:8.04/hardy)
Conf libimlib2 (1.4.0-1ubuntu1 Ubuntu:8.04/hardy)
Conf python-xlib (0.14-1 Ubuntu:8.04/hardy)
Conf pypanel (2.4-1.1build1 Ubuntu:8.04/hardy)
-------------------------------------

Pinning does not work as described in "man apt_preferences," so there is a bug in apt.

[Marco Paolini (mpaolini)]

this does not look like a duplicate of bug #565364

[Julian Andres Klode (juliank)]

It is a duplicate, just maybe with a different effect. Anyway fixed over a year ago in 16.04, no need to bring that up again.