Installing and Holding Stable Packages in Debian Sid


The Blog of Tom Webster

  2016-01-22 15:49:13 PST

Sometimes, running Debian Unstable is... well... unstable. Most of the time it's perfectly stable, it's just bleeding-edge Debian, perfect for my workstations at home, where I want the latest and greatest the FOSS community has to offer. Rarely, a package will just break or come with some nasty bugs. Two I've gotten bit by recently are network-manager and nvidia-driver. These have been fixed recently, but for a bit, the network-manager bug really bummed me out, I wanted a solution to get back to 'normal' (and I had already cleared my apt-cache).

In both cases, I was able to install the package from stable or testing and get back to my original functionality. Today I'll walk you through how to do that.

First, let's make sure we have the ability to use HTTPS with apt:

sudo apt-get install apt-transport-https

I use the https mirrors at kernel.org, so my /etc/apt/sources.list looks like this:

deb https://mirrors.kernel.org/debian/ sid main contrib non-free
deb-src https://mirrors.kernel.org/debian/ sid main contrib non-free
deb https://mirrors.kernel.org/debian/ testing main contrib non-free
deb-src https://mirrors.kernel.org/debian/ testing main contrib non-free
deb https://mirrors.kernel.org/debian/ stable main contrib non-free
deb-src https://mirrors.kernel.org/debian/ stable main contrib non-free

Next, let's set our default release. This will tell apt where we prefer our packages to come from. In my case, I want my packages to come from sid (the codename for Debian unstable).

Add this line to /etc/apt/apt.conf.d/70debconf:

APT::Default-Release "sid";

Note: If you want your default release to be stable or testing, use that instead of sid in the line above.

What this does is tell apt and dpkg that we prefer for our packages to come from the sid release channel, that keeps us on the unstable branch of Debian. Nice and current. To see this in action, run this command:

sudo apt-cache policy network-manager

network-manager:
  Installed: 0.9.10.0-7
  Candidate: 1.0.10-2
  Version table:
    1.0.10-2 990
      990 https://mirrors.kernel.org/debian sid/main amd64 Packages
    1.0.10-1 500
      500 https://mirrors.kernel.org/debian testing/main amd64 Packages
    *** 0.9.10.0-7 500
      500 https://mirrors.kernel.org/debian stable/main amd64 Packages
      100 /var/lib/dpkg/status

See the 990 next to the sid version? That's our pin-priority value, the highest value wins when apt-get looks for a version to install. By setting our default release channel, we've set sid's pin-priority to 990.

For more information on pinning, check out these great resources:

You can now use -t stable to install a package from the stable repositories:

sudo apt-get install -t stable network-manager

Now, that package will be upgraded next time you run updates (even unattended-upgrades will do this), so you need to tell dpkg to hold the package and add it to the "Don't auto-upgrade this one" list:

If you have unattended-upgrades installed and configured, you should see this section in /etc/apt/apt.conf.d/50unattended-upgrades:

// List of packages to not update (regexp are supported)
Unattended-Upgrade::Package-Blacklist {
//      "vim";
//      "libc6";
//      "libc6-dev";
//      "libc6-i686";
};

Add your package to that list:

// List of packages to not update (regexp are supported)
Unattended-Upgrade::Package-Blacklist {
//      "vim";
//      "libc6";
//      "libc6-dev";
//      "libc6-i686";
        "network-manager";
};

Now unattended-upgrades won't upgrade that package, but you still can accidentally upgrade it if you use sudo apt-get upgrade or sudo apt-get dist-upgrade, so here's how to fix that problem:

Run: echo "network-manager hold" | sudo dpkg --set-selections

Note: You don't want to leave packages on hold forever, that would be very very bad. Packages regularly get security updates, and even the bug you suffer from currently will eventually be fixed (watch the Debian bug tracker, it's helpful), so you'll want to remove the hold once a new version of the package has been released. If you keep a package on hold forever, you will compromise the security of your system!

To "unhold" a package, use this command:

echo "network-manager install" | sudo dpkg --set-selections

Now you can sudo apt-get upgrade or sudo apt-get dist-upgrade to get the latest release of the package.

If you have any questions or comments, hit up the section below.