Reorganize and update nixpkgs upstreams

This patch does a few things:

1. Switches from nixpkgs-unstable to nixos-unstable{,-small}, simply because
   nixpkgs-unstable is not in cache.nixos.org, but nixos-unstable is, and -small
   is the same but requires all tests to pass. So we should prefer
   nixos-unstable-small, whenever possible.

2. Reorganizes the nixpkgs import code such that Nixpkgs.nix returns an attrset
   of all the nixpkgs that I want to use, rather than putting other nixpkgs
   branches into the main one as an overlay. This is much simpler and explicit,
   but it meant I had to change a lot of usages throughtout the nix codebase.

3. As a consequence of 2, moves the overlays into separate files so they can be
   re-used across nixpkgs branches.

1 files changed, 8 insertions, 8 deletions

diff --git a/Biz/Bild/Builder.nix b/Biz/Bild/Builder.nix
index 4bef830..d1fc48b 100644
--- a/Biz/Bild/Builder.nix
+++ b/Biz/Bild/Builder.nix
@@ -3,9 +3,9 @@
      wouldn't you?
    - Try to reuse as much upstream Nix as possible.
 */
-{ analysisJSON, nixpkgs ? import ../Bild.nix { } }:
-with nixpkgs;
+{ analysisJSON, bild ? import ../Bild.nix { } }:
 let
+  lib = bild.lib;
   analysis = builtins.fromJSON analysisJSON;
   build = _: target:
     let
@@ -53,7 +53,7 @@ let
       sysdeps_ = if isEmpty target.sysdeps then
         [ ]
       else
-        lib.attrsets.attrVals target.sysdeps pkgs;
+        lib.attrsets.attrVals target.sysdeps bild.pkgs;
 
       rundeps_ = if isEmpty target.rundeps then
         [ ]
@@ -63,16 +63,16 @@ let
       CODEROOT = ".";
 
       builders = {
-        base = stdenv.mkDerivation rec {
+        base = bild.stdenv.mkDerivation rec {
           inherit name src CODEROOT preBuild;
           buildInputs = langdeps_ ++ sysdeps_;
           installPhase = "install -D ${name} $out/bin/${name}";
           buildPhase = compileLine;
         };
 
-        haskell = stdenv.mkDerivation rec {
+        haskell = bild.stdenv.mkDerivation rec {
           inherit name src CODEROOT preBuild;
-          nativeBuildInputs = [ makeWrapper ];
+          nativeBuildInputs = [ bild.makeWrapper ];
           buildInputs = sysdeps_ ++ [
             (bild.haskell.ghcWith
               (p: (lib.attrsets.attrVals target.langdeps p)))
@@ -85,7 +85,7 @@ let
           '';
         };
 
-        c = stdenv.mkDerivation rec {
+        c = bild.stdenv.mkDerivation rec {
           inherit name src CODEROOT preBuild;
           buildInputs = langdeps_ ++ sysdeps_;
           installPhase = "install -D ${name} $out/bin/${name}";
@@ -155,4 +155,4 @@ let
   # return a single drv, so just take the first one for now. ideally i would only
   # pass Target, one at a time, (perhaps parallelized in haskell land) and then i
   # wouldn't need all of this let nesting
-in builtins.head (lib.attrsets.mapAttrsToList build analysis)
+in builtins.head (bild.lib.attrsets.mapAttrsToList build analysis)