This patch makes GTK+ look for additional modules in a list of directories
specified by the environment variable "GUIX_GTK3_PATH".  This can be used
instead of "GTK_PATH" to make GTK+ find modules that are incompatible with
other major versions of GTK+.

--- a/gtk/gtkmodules.c	2015-09-20 20:09:05.060590217 +0200
+++ b/gtk/gtkmodules.c	2015-09-20 20:10:33.423124833 +0200
@@ -52,6 +52,7 @@
 get_module_path (void)
 {
   const gchar *module_path_env;
+  const gchar *module_guix_gtk3_path_env;
   const gchar *exe_prefix;
   gchar *module_path;
   gchar *default_dir;
@@ -61,6 +62,7 @@
     return result;
 
   module_path_env = g_getenv ("GTK_PATH");
+  module_guix_gtk3_path_env = g_getenv ("GUIX_GTK3_PATH");
   exe_prefix = g_getenv ("GTK_EXE_PREFIX");
 
   if (exe_prefix)
@@ -68,7 +70,13 @@
   else
     default_dir = g_build_filename (_gtk_get_libdir (), "gtk-3.0", NULL);
 
-  if (module_path_env)
+  if (module_guix_gtk3_path_env && module_path_env)
+    module_path = g_build_path (G_SEARCHPATH_SEPARATOR_S,
+				module_guix_gtk3_path_env, module_path_env, default_dir, NULL);
+  else if (module_guix_gtk3_path_env)
+    module_path = g_build_path (G_SEARCHPATH_SEPARATOR_S,
+				module_guix_gtk3_path_env, default_dir, NULL);
+  else if (module_path_env)
     module_path = g_build_path (G_SEARCHPATH_SEPARATOR_S,
 				module_path_env, default_dir, NULL);
   else
vices/security-token.scm?id=def0acd5e5c0e8c5e32ac69d9e9a18a536be7962'>commit</a><a href='/guix/diff/gnu/services/security-token.scm?id=def0acd5e5c0e8c5e32ac69d9e9a18a536be7962'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/services/security-token.scm'>
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<tr><td><span title='2021-07-03 20:13:42 +0200'>2021-07-03</span></td><td><a href='/guix/commit/gnu/services/security-token.scm?id=e789ce538ed848bacb8f4eb5742f78b965ccf57c'>services: pcscd: Fix daemon signal handling.</a><span class='msg-avail'>...<span class='msg-tooltip'>"pcscd" wouldn't handle SIGTERM as it inherit ignoring this signal (and
others) from its parent shepherd; fork+exec-command restore signal
handling.  Fixes &lt;https://issues.guix.gnu.org/45202&gt;.

* gnu/services/security-token.scm (pcscd)[start]: Use
fork+exec-command to start "pcscd".
</span></span></td><td>Brice Waegeneire</td></tr>
<tr><td><span title='2021-06-19 23:49:18 +0200'>2021-06-19</span></td><td><a href='/guix/commit/gnu/services/security-token.scm?id=4bed8486d4c0a4ff142903b8bc1584ce84767355'>services: pcscd: Cleanup socket when started.</a><span class='msg-avail'>...<span class='msg-tooltip'>Otherwise when pcscd doesn't terminate properly (ie. receive a SIGKILL),
it won't start again because of it's socket already existing.

* gnu/services/security-token.scm (pcscd-shepherd-service)[start]:
Remove existing socket file.
</span></span></td><td>Brice Waegeneire</td></tr>
<tr><td><span title='2020-12-13 00:35:49 +0100'>2020-12-13</span></td><td><a href='/guix/commit/gnu/services/security-token.scm?id=a4cd86ff4b7a9dd4bf1a5320b8121b470e381b67'>gnu: htop: Update to 3.0.3.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/admin.scm (htop): Update to 3.0.3.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-12-12 23:10:05 +0100'>2020-12-12</span></td><td><a href='/guix/commit/gnu/services/security-token.scm?id=8f2656f1debffe92ea088f4c88cfe8ec560b2ba3'>services: pcscd-shepherd-service: Fix PID file location.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;http://issues.guix.gnu.org/45202&gt;.

* gnu/services/security-token.scm (pcscd-shepherd-service): Look for
pcscd.pid in /run instead of /var/run.

Reported by Raffael Stocker &lt;r.stocker@mnet-mail.de&gt;.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>