Updating from trunk. I had to do some changes to make it fit.

svn path=/nixpkgs/branches/stdenv-updates/; revision=23500

pkgs/misc/emulators/gens-gs/default.nix

@@ -0,0 +1,19 @@
+{ stdenv, fetchurl, pkgconfig, gtkLibs, SDL, nasm, zlib, libpng, mesa }:
+
+stdenv.mkDerivation { 
+  name = "gens-gs-7";
+
+  src = fetchurl {
+    url = http://segaretro.org/images/6/6d/Gens-gs-r7.tar.gz;
+    sha256 = "1ha5s6d3y7s9aq9f4zmn9p88109c3mrj36z2w68jhiw5xrxws833";
+  };
+
+  buildInputs = [ pkgconfig gtkLibs.gtk SDL nasm zlib libpng mesa ];
+
+  meta = {
+    homepage = http://segaretro.org/Gens/GS;
+    description = "A Genesis/Mega Drive emulator";
+    platforms = [ "i686-linux" ];
+    maintainers = [ stdenv.lib.maintainers.eelco ];
+  };
+}

pkgs/misc/tex/texlive/aggregate.nix

@@ -30,7 +30,9 @@ rec {
 
     ensureDir $out/bin
     for i in $out/libexec/*/*; do
-        echo -ne "#! /bin/sh\\n$i \"\$@\"" >$out/bin/$(basename $i)
+        test -f "$i" && \
+	test -x "$i" && \
+	echo -ne "#! /bin/sh\\n$i \"\$@\"" >$out/bin/$(basename $i) && \
         chmod a+x $out/bin/$(basename $i)
     done