From a4cdcffb19f38b47bb7e0234c1244edbede35d59 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= <ludo@gnu.org>
Date: Wed, 29 Mar 2017 13:14:28 +0200
Subject: [PATCH] gnu: lxsession: Build Vala code from source.

* gnu/packages/lxde.scm (lxsession)[source](snippet): New field.
---
 gnu/packages/lxde.scm | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/gnu/packages/lxde.scm b/gnu/packages/lxde.scm
index 0844263713..e7654053d8 100644
--- a/gnu/packages/lxde.scm
+++ b/gnu/packages/lxde.scm
@@ -333,7 +333,20 @@ (define-public lxsession
        (patches (search-patches "lxsession-use-gapplication.patch"))
        (sha256
         (base32
-         "1a0zmyywwzdh59nc0l94cir18vhp633z4q2xfhn5zx11ajj45gwh"))))
+         "1a0zmyywwzdh59nc0l94cir18vhp633z4q2xfhn5zx11ajj45gwh"))
+       (modules '((guix build utils)))
+       (snippet
+        ;; Remove C files generated by Vala so we can build from source.
+        '(let* ((c->vala
+                 (lambda (file)
+                   (string-append (string-drop-right file 2)
+                                  ".vala")))
+                (generated-c-file?
+                 (lambda (file stat)
+                   (and (string-suffix? ".c" file)
+                        (file-exists? (c->vala file))))))
+           (for-each delete-file
+                     (find-files "." generated-c-file?))))))
     (build-system gnu-build-system)
     (arguments
      `(#:phases