From 3b59fbd6083f50ec3723439b549c608bfc6d8009 Mon Sep 17 00:00:00 2001
From: Alexander Flatter <flatter@fastmail.fm>
Date: Mon, 8 Sep 2014 18:44:43 +0200
Subject: [PATCH] WIP

---
 pkgs/development/interpreters/ruby/bundix.nix | 16 ++++++++++++++++
 pkgs/top-level/all-packages.nix               |  8 ++++++--
 2 files changed, 22 insertions(+), 2 deletions(-)
 create mode 100644 pkgs/development/interpreters/ruby/bundix.nix

diff --git a/pkgs/development/interpreters/ruby/bundix.nix b/pkgs/development/interpreters/ruby/bundix.nix
new file mode 100644
index 00000000000..b4cc4bbb31f
--- /dev/null
+++ b/pkgs/development/interpreters/ruby/bundix.nix
@@ -0,0 +1,16 @@
+{rubyLibsWith, callPackage, lib}:
+
+{
+  loadRubyEnv = path: config:
+    let
+      expr = callPackage path {};
+      ruby = config.ruby;
+      rubyLibs = rubyLibsWith ruby;
+      gems = rubyLibs.importGems expr.gemset config.gemOverrides;
+    in {
+      inherit ruby; # TODO: Set ruby using expr.rubyVersion if not given.
+      gemPath = map (drv: "${drv}/${ruby.gemPath}") (
+        builtins.filter (value: lib.isDerivation value) (lib.attrValues gems)
+      );
+    };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 90ce4bf6555..e85d18f01ed 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -4045,10 +4045,14 @@ let
   ruby_2_0 = ruby_2_0_0;
   ruby_2_1 = ruby_2_1_3;
 
-  rubyLibsWith = myruby: callPackage ../development/interpreters/ruby/gems.nix {
-    ruby = myruby;
+  rubyLibsWith = ruby: callPackage ../development/interpreters/ruby/gems.nix {
+    inherit ruby;
   };
 
+  loadRubyEnv = (callPackage ../development/interpreters/ruby/bundix.nix {
+    inherit rubyLibsWith;
+  }).loadRubyEnv;
+
   rubyLibs_1_8_7 = rubyLibsWith ruby_1_8_7;
   rubyLibs_1_9_3 = rubyLibsWith ruby_1_9_3;
   rubyLibs_2_0_0 = rubyLibsWith ruby_2_0_0;