[gentoo-catalyst] Sort of Build Platform

[Shinkan]

Hi there !

I'm quitely new to Gentoo, but I'm loving it, so I have projects with it !
Some of them may require Catalyst in its process from what I understood
about Catalyst.

I'll copy/paste a forum post I've made before I knew there was a mailing
list for Catalyst :

OK, let me expose things differently since I know a little more what I would
like to do and what Gentoo could offer.

- I have a local mirror, which may have overlay packages.
- I have a host system, which have Gentoo setup on it.
- I want to build barely-usable minimal systems that I call "guests" from my
host. Guests would have to be setup on target machines using fdisk and tar
only, or put on a Live{CD,DVD,USB}.

Assuming that I can kinda cross-compile guests binaries from my host system
with emerge (using --root and --portage_configdir, guests have same arch
than host), I would like my host system to entirely build my guest BUT I
want my guest to be extremely minimal. My guest don't have to have
sys-devel/* things like binutils, gcc and so on. It just have to run a few
already compiled C++ binaries. Everything that my guest need will be emerged
from my host.

How can I proceed (the clean way !) from my host to emerge (or copy ?) a
fully minimal system to a host dir, like say /guest/ ?
Did I have to "create" a profile on my local mirror which tells that my
"system" meta-port have almost nothing in it ? How can I do this if it's the
clean way ?
Did I have to use Catalyst ? How can I do this if it's the clean way ?

Many thanks in advance.

-- 
Pierre.
"Sometimes when I'm talking, my words can't keep up with my thoughts. I
wonder why we think faster than we speak. Probably so we can think twice." -
Bill Watterson