uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

pkgs/development/tools/misc/watson-ruby/default.nix

@@ -0,0 +1,31 @@
+{ lib, stdenv, bundlerEnv, ruby, bundlerUpdateScript }:
+
+stdenv.mkDerivation rec {
+  pname = "watson-ruby";
+  version = (import ./gemset.nix).watson-ruby.version;
+
+  dontUnpack = true;
+
+  installPhase = let
+    env = bundlerEnv {
+      name = "watson-ruby-gems-${version}";
+      inherit ruby;
+      # expects Gemfile, Gemfile.lock and gemset.nix in the same directory
+      gemdir = ./.;
+    };
+  in ''
+    mkdir -p $out/bin
+    ln -s ${env}/bin/watson $out/bin/watson
+  '';
+
+  passthru.updateScript = bundlerUpdateScript "watson-ruby";
+
+  meta = with lib; {
+    description = "An inline issue manager";
+    homepage    = "https://goosecode.com/watson/";
+    license     = with licenses; mit;
+    maintainers = with maintainers; [ robertodr nicknovitski ];
+    mainProgram = "watson";
+    platforms   = platforms.unix;
+  };
+}