From 22d7c08dc506f74803b7c61c6cbf156dfe844f02 Mon Sep 17 00:00:00 2001
From: zimbatm <zimbatm@zimbatm.com>
Date: Sun, 28 Feb 2016 16:35:27 +0000
Subject: [PATCH 1/2] lib.trivial: add a new importJSON function

This is meant to be used by packages who often re-generate their inputs.

Producing valid JSON is easier than nix, and also garantees it's purity.
---
 lib/trivial.nix | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/lib/trivial.nix b/lib/trivial.nix
index cda8aa08a20..9821e3c138d 100644
--- a/lib/trivial.nix
+++ b/lib/trivial.nix
@@ -75,4 +75,25 @@ rec {
   min = x: y: if x < y then x else y;
   max = x: y: if x > y then x else y;
 
+  /* Reads a JSON file. It is useful to import pure data into other nix
+     expressions.
+
+     Example:
+
+       mkDerivation {
+         src = fetchgit (importJSON ./repo.json)
+         #...
+       }
+
+       where repo.json contains:
+
+       {
+         "url": "git://some-domain/some/repo",
+         "rev": "265de7283488964f44f0257a8b4a055ad8af984d",
+         "sha256": "0sb3h3067pzf3a7mlxn1hikpcjrsvycjcnj9hl9b1c3ykcgvps7h"
+       }
+
+  */
+  importJSON = path:
+    builtins.fromJSON (builtins.readFile path);
 }

From 6d9cc5408909aa304cd8af25059b129c1652c26e Mon Sep 17 00:00:00 2001
From: zimbatm <zimbatm@zimbatm.com>
Date: Mon, 29 Feb 2016 13:49:29 +0000
Subject: [PATCH 2/2] build-maven: use lib.importJSON

---
 pkgs/build-support/build-maven.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/build-support/build-maven.nix b/pkgs/build-support/build-maven.nix
index ff91828eeca..ba85428ba8c 100644
--- a/pkgs/build-support/build-maven.nix
+++ b/pkgs/build-support/build-maven.nix
@@ -11,7 +11,7 @@
  *        the project.
  */
 infoFile: let
-  info = builtins.fromJSON (builtins.readFile infoFile);
+  info = lib.importJSON infoFile;
 
   script = writeText "build-maven-repository.sh" ''
     ${lib.concatStrings (map (dep: let