[nzlug] Installing conflicts on Debian/Ubuntu

[Daniel Lawson]

> I've got a couple of packages from Ubuntu that conflict, although
> there are no common files.
> I need libapache2-mod-php5, and I'd like to also have
> libapache2-mod-php4.
> Unfortunately, lib*5 lists lib*4 as an explicit conflict.
>
> I can install lib*4 with dpkg --force-conflicts, but every time I
> subsequently run apt-get it tries to relieve me of one or the other
> package.
>
> Does anyone know if apt_preferences can solve this, with Pinning or
> something?
Pinning will hold a particular set of packages to a certain state. It
doesn't really deal with conflicts.

The packages are listed as conflicting for a good reason - you can't
(easily) have both php5 and php4 installed alongside one another in a
single apache instance. There is a concurrent patch you can apply, but
Ubuntu haven't used it.  I suspect even if you manage to get both
versions installed, apache won't like it.

If you *really* need to keep php4 around (and from what I've seen, you
probably don't need to from a technical point of view), I'd suggest
building it from scratch and running a new apache on a different port or
using two machines (perhaps virtual machines), in both cases behind a
reverse proxy or something if needs be.