From a8ded9d5d36ddbf7200a1693c74bd83d1403a8c1 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Tue, 18 Feb 2014 19:11:57 +0100
Subject: [PATCH] fetchgit: Require a content hash

Without this, the result will not be a fixed-output derivation and
won't work in general.
---
 pkgs/build-support/fetchgit/default.nix | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pkgs/build-support/fetchgit/default.nix b/pkgs/build-support/fetchgit/default.nix
index 01424bae30b2..b22bdc88f83b 100644
--- a/pkgs/build-support/fetchgit/default.nix
+++ b/pkgs/build-support/fetchgit/default.nix
@@ -23,6 +23,8 @@
    server admins start using the new version?
 */
 
+assert md5 != "" || sha256 != "";
+
 stdenv.mkDerivation {
   name = "git-export";
   builder = ./builder.sh;