Ubuntu... downgrade? (64-bit -> 32-bit)

[Brian St. Pierre]

On Wed, Jan 26, 2011 at 8:54 AM, Benjamin Scott <dragonhawk at gmail.com> wrote:
> On Tue, Jan 25, 2011 at 11:40 PM, Ken D'Ambrosio <ken at jots.org> wrote:
>> Hmmm... might be worth looking into.  I mean, what's the worst that
>> happens?  I bork my system, and wind up doing a re-install.  Which is what
>> I'm looking at, anyway.  So, yeah -- I'll poke around and see what I can
>> make happen.
>
>  I have an idea I've been turning over in my head which may be
> applicable here, too: Set up another installation in a directory
> branch.  In your case, maybe under "/usr/ubuntu-i386/" or something
> like that.
>
>  The reason I want to do this is so I can get certain things from
> Debian "unstable" to install (with all their library dependencies)
> without having to run my entire system on unstable.[1]
>
>  One way to do this would be to bootstrap an installation in a VM or
> a chroot, but that's a bit heavy-handed.

I used to maintain a 32-bit install inside of my 64-bit install
(debian) with schroot and instructions similar to these:

    http://www.debian-administration.org/articles/566
    https://alioth.debian.org/docman/view.php/30192/21/debian-amd64-howto.html#id292281

I needed it to be able to use a couple of binary-only packages that
were only available as 32-bit.

>  I've been fiddling with using arguments to apt-get/dpkg to change
> the root directory for that invocation, e.g.:
>
>        sudo apt-get -o 'RootDir=/usr/unstable' update
>
>  That problem I have is that I haven't found the magic needed to
> initialize an apt installation.  It rightly complains that its data
> files are missing, but I don't know any way to create them.  With RPM,
> it's "rpm --initdb".  Anyone know how to do it in APT-land?

Take a look at debootstrap, it might do what you want.

-Brian