Gnome-tweaks does not look at GSETTINGS_SCHEMA_PATH or XDG_DATA_DIRS, it
assumes that schemas are installed in one global directory
(GSETTINGS_SCHEMA_DIR/gsettingsschemadir).

Guix/GuixSD uses a different directory for every gir package and has
packages pick-up files using XDG_DATA_DIRS.

Upstream ticket: https://bugzilla.gnome.org/show_bug.cgi?id=764537
janneke@gnu.org

--- gnome-tweak-3.18.1.orig/gtweak/gsettings.py	2015-04-08 15:21:32.000000000 +0200
+++ gnome-tweak-tool-3.18.1/gtweak/gsettings.py	2016-04-03 11:26:38.658482704 +0200
@@ -16,7 +16,8 @@
 # along with gnome-tweak-tool.  If not, see <http://www.gnu.org/licenses/>.
 
 import logging
-import os.path
+import os
+import sys
 import xml.dom.minidom
 import gettext
 
@@ -31,6 +32,13 @@
 class GSettingsMissingError(Exception):
     pass
 
+def file_from_path(path, file_name):
+    for dir in path:
+        f = os.path.join(dir, file_name)
+        if os.path.exists(f):
+            return f
+    return None
+
 class _GSettingsSchema:
     def __init__(self, schema_name, schema_dir=None, schema_filename=None, **options):
         if not schema_dir:
@@ -38,9 +46,14 @@
         if</td></tr></table>
<table class='tabs'><tr><td>
<a href='/rpi-MMU-example/about/'>about</a><a href='/rpi-MMU-example/'>summary</a><a href='/rpi-MMU-example/refs/?id=03e9c87115527eeb21d5c7c554c3a1b6f8211e54'>refs</a><a href='/rpi-MMU-example/log/scheduler.h'>log</a><a href='/rpi-MMU-example/tree/scheduler.h?id=03e9c87115527eeb21d5c7c554c3a1b6f8211e54'>tree</a><a class='active' href='/rpi-MMU-example/commit/scheduler.h?id=03e9c87115527eeb21d5c7c554c3a1b6f8211e54'>commit</a><a href='/rpi-MMU-example/diff/scheduler.h?id=03e9c87115527eeb21d5c7c554c3a1b6f8211e54'>diff</a></td><td class='form'><form class='right' method='get' action='/rpi-MMU-example/log/scheduler.h'>
<input type='hidden' name='id' value='03e9c87115527eeb21d5c7c554c3a1b6f8211e54'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/rpi-MMU-example/commit/?id=03e9c87115527eeb21d5c7c554c3a1b6f8211e54'>root</a>/<a href='/rpi-MMU-example/commit/scheduler.h?id=03e9c87115527eeb21d5c7c554c3a1b6f8211e54'>scheduler.h</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='03e9c87115527eeb21d5c7c554c3a1b6f8211e54'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Wojtek Kosior &lt;kwojtus@protonmail.com&gt;</td><td class='right'>2020-01-02 13:45:41 +0100</td></tr>
<tr><th>committer</th><td>Wojtek Kosior &lt;kwojtus@protonmail.com&gt;</td><td class='right'>2020-01-02 13:45:41 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/rpi-MMU-example/commit/scheduler.h?id=03e9c87115527eeb21d5c7c554c3a1b6f8211e54'>03e9c87115527eeb21d5c7c554c3a1b6f8211e54</a> (<a href='/rpi-MMU-example/patch/scheduler.h?id=03e9c87115527eeb21d5c7c554c3a1b6f8211e54'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/rpi-MMU-example/tree/?id=03e9c87115527eeb21d5c7c554c3a1b6f8211e54'>602190ded1f65961336e0ed12b9261f5bdc178bc</a> /<a href='/rpi-MMU-example/tree/scheduler.h?id=03e9c87115527eeb21d5c7c554c3a1b6f8211e54'>scheduler.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/rpi-MMU-example/commit/scheduler.h?id=7da46d099e1d1909bf5d09ecedfea21481a7a3b9'>7da46d099e1d1909bf5d09ecedfea21481a7a3b9</a> (<a href='/rpi-MMU-example/diff/scheduler.h?id=03e9c87115527eeb21d5c7c554c3a1b6f8211e54&amp;id2=7da46d099e1d1909bf5d09ecedfea21481a7a3b9'>diff</a>)</td></tr><tr><th>download</th><td colspan='2' class='oid'><a href='/rpi-MMU-example/snapshot/rpi-MMU-example-03e9c87115527eeb21d5c7c554c3a1b6f8211e54.tar.gz'>rpi-MMU-example-03e9c87115527eeb21d5c7c554c3a1b6f8211e54.tar.gz</a><br/><a href='/rpi-MMU-example/snapshot/rpi-MMU-example-03e9c87115527eeb21d5c7c554c3a1b6f8211e54.zip'>rpi-MMU-example-03e9c87115527eeb21d5c7c554c3a1b6f8211e54.zip</a><br/></td></tr></table>
<div class='commit-subject'>fix/improve arm timer register definitions</div><div class='commit-msg'></div><div class='diffstat-header'><a href='/rpi-MMU-example/diff/?id=03e9c87115527eeb21d5c7c554c3a1b6f8211e54'>Diffstat</a> (limited to 'scheduler.h')</div><table summary='diffstat' class='diffstat'>