[PATCH 02/14] guix: build all Python packages with --single-version-externally-managed.

[Hartmut Goebel]

This requires setuptools to be installed together with python, which is
the case for Python 3 anyway and which we do for our build of Python 2
(see last commit).

* guix/build/python-build-system.scm (install): Add
  "--single-version-externally-managed" and "--root=/" to params to be
  passed to call-setuppy. Remove thus needless manipulation of
  PYTHONPATH.
---
 guix/build/python-build-system.scm | 17 ++++-------------
 1 file changed, 4 insertions(+), 13 deletions(-)

diff --git a/guix/build/python-build-system.scm 
b/guix/build/python-build-system.scm
index 9109fb4..8d4d6d3 100644
--- a/guix/build/python-build-system.scm
+++ b/guix/build/python-build-system.scm
@@ -3,6 +3,7 @@
 ;;; Copyright © 2013 Andreas Enge <address@hidden>
 ;;; Copyright © 2013 Nikita Karetnikov <address@hidden>
 ;;; Copyright © 2015 Mark H Weaver <address@hidden>
+;;; Copyright © 2016 Hartmut Goebel <address@hidden>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -65,19 +66,9 @@
   "Install a given Python package."
   (let* ((out (assoc-ref outputs "out"))
          (params (append (list (string-append "--prefix=" out))
-                         configure-flags))
-         (python-version (get-python-version (assoc-ref inputs "python")))
-         (old-path (getenv "PYTHONPATH"))
-         (add-path (string-append out "/lib/python" python-version
-                                  "/site-packages/")))
-        ;; create the module installation directory and add it to PYTHONPATH
-        ;; to make setuptools happy
-        (mkdir-p add-path)
-        (setenv "PYTHONPATH"
-                (string-append (if old-path
-                                   (string-append old-path ":")
-                                   "")
-                               add-path))
+                         "--single-version-externally-managed"
+                         "--root=/"
+                         configure-flags)))
         (call-setuppy "install" params)))
 
 (define* (wrap #:key inputs outputs #:allow-other-keys)
-- 
2.7.4