How to go back to previous version of Thunderbird on 18.04?

Solution 1:

Step 1 - Find the version you want

apt policy or apt-cache policy (or apt-cache madison)

e.g.

$ sudo apt policy thunderbird
thunderbird:
  Installed: 1:60.2.1+build1-0ubuntu0.18.04.2
  Candidate: 1:60.2.1+build1-0ubuntu0.18.04.2
  Version table:
 *** 1:60.2.1+build1-0ubuntu0.18.04.2 500
        500 http://au.archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu bionic-security/main amd64 Packages
     1:52.7.0+build1-0ubuntu1 500
        500 http://au.archive.ubuntu.com/ubuntu bionic/main amd64 Packages

So now we know (at this time) we have two versions:

• 1:60.2.1+build1-0ubuntu0.18.04.2 and
• 1:52.7.0+build1-0ubuntu1

The three stars *** indicates that this is the version currently installed as per the "Installed:" line.

Step 2 - Install another version

This is easy, just use the syntax [packagename]=[version] with apt install.

e.g.

$ sudo apt install thunderbird=1:52.7.0+build1-0ubuntu1
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Suggested packages:
  thunderbird-gnome-support ttf-lyx
The following packages will be DOWNGRADED:
  thunderbird
0 to upgrade, 0 to newly install, 1 to downgrade, 0 to remove and 12 not to upgrade.
Need to get 46.5 MB of archives.
After this operation, 38.4 MB disk space will be freed.
Do you want to continue? [Y/n]

Note the warning that the package will be DOWNGRADED

Bonus step - lock in that version (a.k.a. apt-mark hold)

If you want to stop apt upgrade from upgrading the package again, then you can tell apt to hold a package.

e.g.

$ sudo apt-mark hold thunderbird
thunderbird set on hold.

So now, when you apt upgrade you'll get a warning that packages have been kept back. e.g.

$ sudo apt upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
The following packages have been kept back:
  thunderbird
0 to upgrade, 0 to newly install, 0 to remove and 1 not to upgrade.

When you are comfortable upgrading again, then you can release the hold:

$ sudo apt-mark unhold thunderbird
Cancelled hold on thunderbird.

e voila, the latest release is now the default again:

$ sudo apt upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
The following packages will be upgraded:
  thunderbird
1 to upgrade, 0 to newly install, 0 to remove and 0 not to upgrade.
Need to get 41.1 MB of archives.
After this operation, 38.4 MB of additional disk space will be used.
Do you want to continue? [Y/n]

You could also have gone with apt pinning and the /etc/apt/preferences file but holding is much easier for this task!