[Nix-dev] Re: Porting NixOS

[Ludovic Courtès]

Hi,

Eelco Dolstra <e.dolstra at tudelft.nl>
writes:

> I don't think I would like separating the Nix expressions for non-free packages
> from Nixpkgs, since that would make live more difficult for users who do want to
> use a non-free package (say the NVIDIA driver), but it would be a good idea (as
> discussed before) to have a meta attribute to mark non-free packages.  Then the
> system can automatically warn you if there are any non-free packages in the
> dependency graph of a particular configuration.  This would also help us to
> prevent non-free packages from being distributed (in binary form) in the Nixpkgs
> channel, which has happened accidentally in the past (e.g. Java 5 due to free
> packages having it as a dependency).

I think the best solution would be to leverage the existing
`meta.license' attribute to that end.  The problem is that many packages
currently lack that attribute, especially non-free packages.

As a starting point, `nix-env' could be augmented, say, with a `--free'
option such that it aborts when an element of the dependency graph as
"non-free" as `meta.license' or lacks `meta.license'.  That would give
people interested in free software an incentive to add `meta.license' to
free software packages that lack it.  What do you think?

> OTOH when we have such an attribute, we can easily generate a Nixpkgs
> distribution that doesn't contain non-free packages.

The main question will be whether the "official NixOS ISO" should
include non-free packages, since the user can only really choose once
the base system is installed.

Thanks,
Ludo'.