[Nix-dev] fetchFrom* improvement

[Jan Malakhovski]

Eelco Dolstra <eelco.dolstra at logicblox.com> writes:

> What the point in having meta information attached to fetchurl results? They
> won't show up in nix-env queries...
>
> It also makes the assumption that the source repository of a package is its
> homepage, which is questionable.

That patch does not inherit `homepage` in stdenv.mkDerivation (that
would be a bit problematic since fetchurl itself uses
stdenv.mkDerivation).

The idea of that glorious change is to avoid retyping the url and just
write

    meta = { homepage = src.homepage; };

for the packages that do have their github/bitbucket/... pages as
homepages.

Derived mkDerivations can actually set this as the default if they wish.
E.g. my WIP branch
https://github.com/NixOS/nixpkgs/compare/master...oxij:emacs-packages-cleanup
does this for emacs (because of all the current emacs package collection
there're only three packages that are exceptions to this rule).

Cheers,
  Jan