Adapt pkgsrc to create a package system with dependency independence

[Christophe Romain]

Hello

I'm an opensourcer since 96, following dfbsd for about 3 years, interrested in
general packaging issues, and involved in packaging Erlang software.
I'm pleased to read some concerns on packaging improvements for pkgsrc.
You mention PC-BSD's PBI. While PBI is a simple implementation, it is really
not efficient, and does not solves all packaging issues.
I think a good direction would be to write some tools to make pkgsrc
Nix aware, or interract with nix itself. (see http://nixos.org/nix/)
Nix manages packages "profiles" allowing several version of same package
being installed, allows library upgrade without interfering other
packages that use that library. It also allows live installation rollback,
and even allows same version of a given package being installed with
different build options or compilation chain, very handy to have, let
say, a standard library installed, and the same with gcc optimizations
enabled, both installed on the same system, the optimized version being
only used by 'devel' user.
While it's possible to install and use nix on BSD, it actually does
not benefits huge work done on pkgsrc, as it needs nix expressions to
build package. It's also not integrated to the system.
I think this would be a real benefit for pkgsrc users to drop all
outdated packaging ideas, and explore the nix way as an optional target.
any thoughts ?

best regards.