Pin down nixpkgs

domenkozar · domenkozar · commit fbb569b7759a · 2017-11-08T19:11:50.000Z
diff --git a/default.nix b/default.nix
@@ -1,4 +1,4 @@
-{ pkgs ? import <nixpkgs> {}}:
+{ pkgs ? import (import ./fetch-nixpkgs.nix) {} }:
 
 with pkgs.haskell.lib;
 
diff --git a/fetch-nixpkgs.nix b/fetch-nixpkgs.nix
@@ -0,0 +1,23 @@
+let
+  spec = builtins.fromJSON (builtins.readFile ./nixpkgs-src.json);
+  src = import <nix/fetchurl.nix> {
+    url = "https://github.com/${spec.owner}/${spec.repo}/archive/${spec.rev}.tar.gz";
+    inherit (spec) sha256;
+  };
+  nixcfg = import <nix/config.nix>;
+in builtins.derivation {
+  system = builtins.currentSystem;
+  name = "${src.name}-unpacked";
+  builder = builtins.storePath nixcfg.shell;
+  inherit src;
+  args = [
+    (builtins.toFile "builder" ''
+      $coreutils/mkdir $out
+      cd $out
+      $gzip -d < $src | $tar -x --strip-components=1
+    '')
+  ];
+  coreutils = builtins.storePath nixcfg.coreutils;
+  tar = builtins.storePath nixcfg.tar;
+  gzip = builtins.storePath nixcfg.gzip;
+}
diff --git a/nixpkgs-src.json b/nixpkgs-src.json
@@ -0,0 +1,6 @@
+{
+    "owner":  "NixOS",
+    "repo":   "nixpkgs",
+    "rev":    "61fbdb47a69f78998f55207e64122a0798047b5d",
+    "sha256": "050r55sgpy121j5qs00jw43rg5pnqidbdbvvj4lr1i9lmv9f1vfv"
+}
diff --git a/scripts/travis.sh b/scripts/travis.sh
@@ -2,7 +2,10 @@
 #! nix-shell -p cabal2nix stack nix-prefetch-git git cabal-install ghc -i bash
 #! nix-shell -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/a905b7cd0c2dc0714195a50bf176cd8e4593502d.tar.gz
 
-export NIX_PATH=nixpkgs=https://github.com/NixOS/nixpkgs/archive/a905b7cd0c2dc0714195a50bf176cd8e4593502d.tar.gz
+readlink=$(nix-instantiate --eval -E "/. + (import <nix/config.nix>).coreutils")/readlink
+scriptDir=$(dirname -- "$($readlink -f -- "${BASH_SOURCE[0]}")")
+export NIX_PATH="nixpkgs=$(nix-build "${scriptDir}/../fetch-nixpkgs.nix" --no-out-link)"
+
 
 set -ex
 

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-{ pkgs ? import <nixpkgs> {}}:`
	`1`	`+{ pkgs ? import (import ./fetch-nixpkgs.nix) {} }:`
`2`	`2`
`3`	`3`	`with pkgs.haskell.lib;`
`4`	`4`