Re: [gentoo-portage-dev] DB and binary dependency

[Paul de Vrieze]

On Thursday 23 March 2006 20:53, tvali wrote:
> So this interaction is one more thing to get simpler? I'm starting to think
> that i should seek for some very-very small part of portage to develop,
> because size of things [amount of work], which i already think i should
> improve in some way, is getting to somewhere near infinity :) ...ok, near
> what infinity is for me, not theoretical infinity ;)
>
> What is the simplest way to get one portage running in some virtual space
> where i could install and uninstall without actually changing my system?
> Using chroot in the same way as when installing gentoo is good?

Certainly,

chroot combined with lvm snapshots would be the easiest way.

If you want to focus on binary packages, you might want to start with not 
doing it automatically, but using some crude heuristics. You can make it 
configurable for when the heuristics don't work.

Basically what is the difference between a binary package and the source 
package is the dependencies.

You can regard a dependency as a restriction on the configurations in which 
the package can be installed. For binary packages only runtime dependencies 
are relevant (well in gentoo anyway, we don't have initial configuration 
deps). Binary packages do however further restrict the configurations from 
the runtime dependencies. These restrictions originate from the configuration 
when compiling the package.

Then I have some good and bad news. The good news:
- Binary dependencies are as necessary for binary packages, as for validating
  a current configuration (set of installed packages).
The bad:
- For proper binary dependencies the depend expression possibilities must be
  extended. Useflag dependencies would be at least usefull. BINSLOT would be
  almost required. We already saw that SLOT can't always be used for BINSLOT.

Paul

-- 
Paul de Vrieze
Gentoo Developer
Mail: pauldv@g.o
Homepage: http://www.devrieze.net