Downgrading

[Mark Bucciarelli <mark@easymailings.com>]

Is there a safe way to downgrade packages in Debian?

The dpkg man page has the scary warning that no dependency checking is
done and the apt-get man page just says downgrades "must be used with
care."  Heh.

Before I upgrade my functioning testing boxes to Sarge, I would like to
know how to back out the upgrade, if necessary.

Obviously, I can do this:

cd /var/cache/apt/archives
dpkg -i package-1.deb

But how can I be sure that downgrading, for example, from package-2 to
package-1 doesn't break other deb's that depend on package-2?

If there is no such script out there, how might I write one?  There are
hundreds of packages to upgrade.

m