> If you append (package-native-search-paths python) to the list of search
> paths, then PYTHONPATH will automagically be defined appropriately (see
> <http://lists.gnu.org/archive/html/bug-guix/2013-03/msg00158.html>.)

> If you don’t, then PYTHONPATH will be undefined, unless you explicitly
> define it in build/python-build-system.scm, which is not the recommended
> option.

> So just mimic the change made in the above commit for perl-build-system.

OK, I've added it.  Should I remove the following part?

+  (let* ((out  (assoc-ref outputs "out"))
+         (var `("PYTHONPATH" prefix
+                (,(string-append out "/lib/python"
+                                 python-version "/site-packages")))))
+    (for-each (lambda (dir)
+                (let ((files (list-of-files dir)))
+                  (for-each (cut wrap-program <> var)
+                            files)))
+              bindirs)))

Or is it a different issue?  If both do the same thing, the
'package-native-search-paths' approach feels more verbose.  Because one
should specify it in recipes.  Am I mistaken?

Can I push both patches to 'master'?