From 081343f099d3efabe8ed41a9d10e4ba7319f979e Mon Sep 17 00:00:00 2001
From: Joel Taylor <me@joelt.io>
Date: Wed, 13 Aug 2014 12:13:27 -0700
Subject: [PATCH] gem build updates

---
 pkgs/development/interpreters/ruby/gem.nix | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/pkgs/development/interpreters/ruby/gem.nix b/pkgs/development/interpreters/ruby/gem.nix
index bb0bc2e4863..e226d5cf9e0 100644
--- a/pkgs/development/interpreters/ruby/gem.nix
+++ b/pkgs/development/interpreters/ruby/gem.nix
@@ -29,14 +29,21 @@ in ruby.stdenv.mkDerivation (attrs // {
     };
 
   unpackPhase = ''
-    gem unpack $src --target=gem-build
-    cd gem-build/*
+    if test -d $src; then
+      cd $src
+    else
+      gem unpack $src --target=gem-build
+      cd gem-build/*
+    fi
   '';
 
   buildPhase = ''
     runHook preBuild
-    ${git}/bin/git init
-    ${git}/bin/git add .
+    test -d .git || {
+      chmod 755 .
+      ${git}/bin/git init
+      ${git}/bin/git add .
+    }
     if gem build *.gemspec; then
       export src=*.gem
     else