[bug#35641] [PATCH] services: gdm: Include user profile in D-Bus paths.

[Timothy Sample]

Hi Guix,

I avoided doing this when fixing up GDM because it seemed a little
ham-fisted (clumsy).  However, I think it is better than all the ink
that would be spilled on help-guix without it.

In short, the point is to make sure that D-Bus services included in a
user’s profile can be found and started by the session bus.  This means
that if you are using GDM and install “evolution-data-server” and
“gnome-calendar” (for example), the session bus will be able to start
all of the services that GNOME Calendar needs to function correctly.
There are a handful of major GNOME applications that need this.

Furthermore, I think we should add “evolution-data-server” as a
propagated input for packages that require it.  This way, things like
“guix install evolution” will just work the way one expects.

Is it okay to assume that “.guix-profile” is the user’s profile like
this?  If it isn’t okay in general, is it okay enough for now?

>From e32c27dfa950d250520c3c8ecccba90add863639 Mon Sep 17 00:00:00 2001
From: Timothy Sample <address@hidden>
Date: Wed, 8 May 2019 09:13:14 -0400
Subject: [PATCH] services: gdm: Include user profile in D-Bus paths.

This partially addresses <https://bugs.gnu.org/35267>.

* gnu/services/xorg.scm (dbus-daemon-wrapper): When '$HOME' is set,
include directories from '$HOME/.guix-profile' in the search paths of
the D-Bus daemon.
---
 gnu/services/xorg.scm | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/gnu/services/xorg.scm b/gnu/services/xorg.scm
index 65e9d48915..027524f11d 100644
--- a/gnu/services/xorg.scm
+++ b/gnu/services/xorg.scm
@@ -767,14 +767,24 @@ the GNOME desktop environment.")
          (shell (file-append shadow "/sbin/nologin")))))
 
 (define dbus-daemon-wrapper
-  (program-file "gdm-dbus-wrapper"
-                #~(begin
-                    (setenv "XDG_CONFIG_DIRS"
-                            "/run/current-system/profile/etc/xdg")
-                    (setenv "XDG_DATA_DIRS"
-                            "/run/current-system/profile/share")
-                    (apply execl (string-append #$dbus "/bin/dbus-daemon")
-                           (program-arguments)))))
+  (program-file
+   "gdm-dbus-wrapper"
+   #~(begin
+       (use-modules (srfi srfi-26))
+       (let* ((system-profile "/run/current-system/profile")
+              (user-profile (and=> (getenv "HOME")
+                                   (cut string-append <> "/.guix-profile")))
+              (profiles (if user-profile
+                            (list user-profile system-profile)
+                            (list system-profile))))
+         (setenv "XDG_CONFIG_DIRS"
+                 (string-join (map (cut string-append <> "/etc/xdg") profiles)
+                              ":"))
+         (setenv "XDG_DATA_DIRS"
+                 (string-join (map (cut string-append <> "/share") profiles)
+                              ":"))
+         (apply execl (string-append #$dbus "/bin/dbus-daemon")
+                (program-arguments))))))
 
 (define-record-type* <gdm-configuration>
   gdm-configuration make-gdm-configuration
-- 
2.21.0