From a8217711ce0289c653506e852a065c8190781cc9 Mon Sep 17 00:00:00 2001
From: Eric Seidel <gridaphobe@gmail.com>
Date: Mon, 4 Jan 2016 15:08:45 -0800
Subject: [PATCH] fetchgitLocal: make it work in submodules

---
 pkgs/build-support/fetchgitlocal/default.nix | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pkgs/build-support/fetchgitlocal/default.nix b/pkgs/build-support/fetchgitlocal/default.nix
index 830133b982d..60803ddcb1f 100644
--- a/pkgs/build-support/fetchgitlocal/default.nix
+++ b/pkgs/build-support/fetchgitlocal/default.nix
@@ -10,9 +10,9 @@ let
       preferLocalBuild = true;
     } ''
       cd ${srcStr}
-      ROOT=$(git rev-parse --show-toplevel) # path to repo
+      DOT_GIT=$(git rev-parse --resolve-git-dir .git) # path to repo
 
-      cp $ROOT/.git/index $ROOT/.git/index-user # backup index
+      cp $DOT_GIT/index $DOT_GIT/index-user # backup index
       git reset # reset index
       git add . # add current directory
 
@@ -21,7 +21,7 @@ let
       git rev-parse $(git write-tree) \
         | tr -d '\n' > $out
 
-      mv $ROOT/.git/index-user $ROOT/.git/index # restore index
+      mv $DOT_GIT/index-user $DOT_GIT/index # restore index
     '';
 
   gitHash = builtins.readFile gitHashFile; # cache against git hash