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 . 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 not schema_filename: schema_filename = schema_name + ".gschema.xml" + schema_prefix = os.path.join('glib-2.0', 'schemas') schema_path = os.path.join(schema_dir, schema_filename) if not os.path.exists(schema_path): - logging.critical("Could not find schema %s" % schema_path) + schema_path = file_from_path(os.environ.get ('GSETTINGS_SCHEMA_PATH', '').split(os.path.pathsep), schema_filename) + if not (schema_path and os.path.exists(schema_path)): + schema_path = file_from_path(os.environ.get ('XDG_DATA_DIRS', '').split(os.path.pathsep), os.path.join(schema_prefix, schema_filename)) + if not (schema_path and os.path.exists(schema_path)): + logging.critical("Coul
find schema %s" % schema_filename)
             assert(False)
 
         self._schema_name = schema_name