Ubuntu. Downgrading PHP from 5.3.2 to 5.2.10

Some time ago, I upgraded my Ubuntu installation to 10.04, which also updated all the packages to the versions in the new Ubuntu release’s repository. This didn’t suit me, because PHP was now at 5.3.2 and Zend Optimizer didn’t work with it, and I urgently needed it on my work system.

How do you downgrade?

We need to add the old repositories.
Add the following to the end of the file “/etc/apt/sources.list”:

deb http://ru.archive.ubuntu.com/ubuntu/ karmic main restricted
deb-src http://ru.archive.ubuntu.com/ubuntu/ karmic main restricted

Next, go to “System > Administration > Synaptic Package Manager” and click “Reload” (1).
Then select the “php5” package (2) (and any others that need downgrading), press “Ctrl+E” (or choose “Package > Force Version…” (3)), and select the version—in my case, “5.2.10” (4).

If version “5.2.10” doesn’t appear in Force Version, go to “Settings > Repositories > Other Software” and select the repositories you specified at the end of the file “/etc/apt/sources.list”.