[Nix-dev] Bundling nix-expressions with source code

[Eelco Dolstra]

Hi,

On 22/01/13 13:05, Rickard Nilsson wrote:

> I would like to bundle nix-expressions with some of my self-developed  
> programs, and just let nixpkgs (or some custom-nixpkgs) use the  
> nix-expression from the source when building the program. Is this a wise  
> thing to do? Is it even possible?

It's possible but unfortunately not a good idea.  Doing this:

>    myprog_src = fetchgit { ... };
> 
>    myprog = callPackage "${myprog_src}/default.nix" { };

in Nixpkgs means that an operation like "nix-env -qa '*'" will need to build
myprog_src first, which won't work because query operations open the Nix store
in read-only mode.

OTOH, if you just want to use Nixpkgs inside another project, like Marc said,
you can just do something like:

  with import <nixpkgs> {};

  stdenv.mkDerivation {
    name = "my-pkg";
    src = ./.;
    buildInputs = [ qt4 ... ];
  };

> Obviously, the above example does not work. 

It actually does work in some cases, e.g. "nix-build -A myprog" should work.

-- 
Eelco Dolstra | LogicBlox, Inc. | http://nixos.org/~eelco/