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/authentication.scm?id=645aeaf52dfae66506e382f632042bc7fa4643a2'>commit</a><a href='/guix/diff/gnu/services/authentication.scm?id=645aeaf52dfae66506e382f632042bc7fa4643a2'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/services/authentication.scm'>
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<div class='path'>path: <a href='/guix/log/?id=645aeaf52dfae66506e382f632042bc7fa4643a2'>root</a>/<a href='/guix/log/gnu?id=645aeaf52dfae66506e382f632042bc7fa4643a2'>gnu</a>/<a href='/guix/log/gnu/services?id=645aeaf52dfae66506e382f632042bc7fa4643a2'>services</a>/<a href='/guix/log/gnu/services/authentication.scm?id=645aeaf52dfae66506e382f632042bc7fa4643a2'>authentication.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/services/authentication.scm?id=645aeaf52dfae66506e382f632042bc7fa4643a2&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2023-05-11 13:21:45 +0200'>2023-05-11</span></td><td><a href='/guix/commit/gnu/services/authentication.scm?id=2df5d4fd18a2fbcb8066a50e2da8ec64635f5162'>system: pam: Let PAM extensions add shepherd requirements.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/system/pam.scm (&lt;pam-extension&gt;): New record type.
(pam-shepherd-service): Add Shepherd synchronization point.

* gnu/services/mail.scm (dovecot-shepherd-service)
* gnu/services/lightdm.scm (lightdm-shepherd-service)
* gnu/services/mail.scm (opensmtpd-shepherd-service)
* gnu/services/sddm.scm (sddm-shepherd-service)
* gnu/services/ssh.scm (lsh-shepherd-service, openssh-shepherd-service)
* gnu/services/xorg.scm (slim-shepherd-service, gdm-shepherd-service)
* gnu/services/base.scm (greetd-shepherd-services): Add PAM requirement.

* gnu/system/pam.scm (/etc-entry, extend-configuration,
pam-root-service-type, pam-root-service)
* gnu/services/authentication.scm (pam-ldap-pam-service)
* gnu/services/base.scm (pam-limits-service-type)
(greetd-pam-service)
* gnu/services/desktop.scm (pam-gnome-keyring)
* gnu/services/kerberos.scm (pam-krb5-pam-service)
* gnu/services/pam-mount.scm (pam-mount-pam-service): Adapt to use
pam-extension.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Josselin Poiret</td></tr>
<tr><td><span title='2022-06-15 00:25:21 +0200'>2022-06-15</span></td><td><a href='/guix/commit/gnu/services/authentication.scm?id=8cb1a49a3998c39f315a4199b7d4a121a6d66449'>services: configuration: Use *unspecified* instead of 'disabled.</a><span class='msg-avail'>...<span class='msg-tooltip'>Use *unspecified* as a marker for field values that have not been set.

Rationale: 'disabled may easily clash with user values for boolean fields, is
confusing (i.e. its meaning is *not* boolean false, but unspecified) and it
also passes silently through the symbol? predicate of a field of type symbol.

* gnu/services/configuration.scm (configuration-missing-default-value):
Renamed from configuration-no-default-value.
(define-maybe-helper): Use *unspecified* instead of 'disabled, and make
the default value optional.
* gnu/home/services/desktop.scm (home-redshift-configuration):
Change (maybe-xyz 'disabled) to maybe-xyz.
* gnu/services/authentication.scm (nslcd-configuration): Likewise.
* gnu/services/cgit.scm (repository-cgit-configuration): Likewise.
* gnu/services/file-sharing.scm (serialize-maybe-string)
(serialize-maybe-file-object): Use 'unspecified?' instead of (eq? val
'disabled).
* gnu/services/messaging.scm (raw-content?): Likewise.
(ssl-configuration): Change (maybe-xyz 'disabled) to maybe-xyz.
(prosody-configuration): Likewise.
* gnu/services/file-sharing.scm (transmission-daemon-configuration):
Likewise.
* gnu/services/messaging.scm (define-all-configurations):
Use *unspecified* instead of 'disabled'.
* gnu/services/networking.scm (opendht-configuration): Likewise.
* gnu/services/pm.scm (tlp-configuration): Likewise.
* gnu/services/telephony.scm (jami-account): Likewise.
(jami-configuration): Likewise.
* gnu/services/vpn.scm (openvpn-client-configuration): Likewise.
* tests/services/configuration.scm ("maybe type, no default")
("maybe type, with default"): New tests.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Attila Lendvai</td></tr>
<tr><td><span title='2021-11-30 01:08:55 +0100'>2021-11-30</span></td><td><a href='/guix/commit/gnu/services/authentication.scm?id=892f1b7273d57b25940700877a02618fe826cc08'>services: Accept &lt;inferior-package&gt;s in lieu of &lt;package&gt;s.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/services/authentication.scm (fprintd-configuration)
(nslcd-configuration): Substitute file-like objects for package ones.
* gnu/services/cgit.scm (cgit-configuration, opaque-cgit-configuration):
Likewise.
* gnu/services/cups.scm (package-list?, cups-configuration): Likewise.
* gnu/services/dns.scm (verify-knot-configuration)
(ddclient-configuration): Likewise.
* gnu/services/docker.scm (docker-configuration): Likewise.
* gnu/services/file-sharing.scm (transmission-daemon-configuration): Likewise.
* gnu/services/getmail.scm (getmail-configuration): Likewise.
* gnu/services/mail.scm (dovecot-configuration)
(opaque-dovecot-configuration): Likewise.
* gnu/services/messaging.scm (prosody-configuration)
(opaque-prosody-configuration): Likewise.
* gnu/services/monitoring.scm (zabbix-server-configuration)
(zabbix-agent-configuration): Likewise.
* gnu/services/networking.scm (opendht-configuration): Likewise.
* gnu/services/pm.scm (tlp-configuration): Likewise.
* gnu/services/telephony.scm (jami-configuration): Likewise.
* gnu/services/virtualization.scm (libvirt-configuration)
(qemu-guest-agent-configuration): Likewise.
* gnu/services/vpn.scm (openvpn-client-configuration): Likewise.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>