In nodePackages.patchSource, make the source tree writable

Signed-off-by: Shea Levy <shea@shealevy.com>

pkgs/top-level/node-packages.nix

@@ -17,9 +17,10 @@ rec {
       mkdir unpack
       cd unpack
       unpackFile ${src}
+      chmod -R +w */
       mv */ package 2>/dev/null || true
       sed -i -e "s/:\s*\"latest\"/:  *\"*\"/" -e "s/:\s*\"git\(\+\(ssh\|http\|https\)\)\?\:\/\/[^\"]*\"/: \"*\"/" package/package.json
-      mv * $out
+      mv */ $out
     '';
 
   # Backwards compat