This is copied from NixOS, which is under MIT licence.
https://github.com/NixOS/nixpkgs/blob/master/pkgs/desktops/gnome/misc/gpaste/
diff --git a/src/gnome-shell/extension.js b/src/gnome-shell/extension.js
index c8773fd6..9efbed67 100644
--- a/src/gnome-shell/extension.js
+++ b/src/gnome-shell/extension.js
@@ -6,6 +6,8 @@
 
 const Config = imports.misc.config;
 
+imports.gi.GIRepository.Repository.prepend_search_path('@typelibPath@');
+
 imports.gi.versions.Clutter = Config.LIBMUTTER_API_VERSION;
 imports.gi.versions.GLib = '2.0';
 imports.gi.versions.GPaste = '2';
diff --git a/src/gnome-shell/prefs.js b/src/gnome-shell/prefs.js
index 32244ab2..74b85572 100644
--- a/src/gnome-shell/prefs.js
+++ b/src/gnome-shell/prefs.js
@@ -6,6 +6,8 @@
 
 imports.gi.versions.GPasteGtk = '4';
 
+imports.gi.GIRepository.Repository.prepend_search_path('@typelibPath@');
+
 const ExtensionUtils = imports.misc.extensionUtils;
 
 const { GPasteGtk } = imports.gi;
diff --git a/src/libgpaste/gpaste/gpaste-settings.c b/src/libgpaste/gpaste/gpaste-settings.c
index 7e53eb64..57c399fc 100644
--- a/src/libgpaste/gpaste/gpaste-settings.c
+++ b/src/libgpaste/gpaste/gpaste-settings.c
@@ -1013,7 +1013,11 @@ create_g_settings (void)
     }
     else
     {
-        return g_settings_new (G_PASTE_SETTINGS_NAME);
+        // library used by introspection requires schemas but we cannot set XDG_DATA_DIRS for the library
+        GSettingsSchemaSource *schema_source = g_settings_schema_source_new_from_directory ("@gschemasCompiled@", NULL, FALSE, NULL);
+        g_autoptr (GSettingsSchema) schema = g_settings_schema_source_lookup (schema_source, G_PASTE_SETTINGS_NAME, FALSE);
+        g_settings_schema_source_unref (schema_source);
+        return g_settings_new_full (schema, NULL, NULL);
     }
 }
 
'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='/guix/log/?id=e401eff97706dc6cdaf20b01dd12e291d7d13c2b'>root</a>/<a href='/guix/log/build-aux?id=e401eff97706dc6cdaf20b01dd12e291d7d13c2b'>build-aux</a>/<a href='/guix/log/build-aux/build-self.scm?id=e401eff97706dc6cdaf20b01dd12e291d7d13c2b'>build-self.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/build-aux/build-self.scm?id=e401eff97706dc6cdaf20b01dd12e291d7d13c2b&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-11-27 00:49:53 +0100'>2021-11-27</span></td><td><a href='/guix/commit/build-aux/build-self.scm?id=5c1ba739d432397e7107021fd6cb3ec01aecfb64'>build-self: Help users to submit useful bug reports.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2021-04-29 11:24:48 -0400'>2021-04-29</span></td><td><a href='/guix/commit/build-aux/build-self.scm?id=fbc2a52a32ddc664db8ebab420c2e17b1432c744'>download: Use Disarchive as a last resort.</a><span class='msg-avail'>...</span></td><td>Timothy Sample</td></tr>
<tr><td><span title='2021-04-01 14:58:55 +0200'>2021-04-01</span></td><td><a href='/guix/commit/build-aux/build-self.scm?id=a81a19930b2cbe1327e1e82d6210f80846ce2898'>build-self: Take care of the spinner in the parent process.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-04-01 14:58:55 +0200'>2021-04-01</span></td><td><a href='/guix/commit/build-aux/build-self.scm?id=1c10c2751a9075db5ab70fd102f0cc5ef2375720'>build-self: Forward sub-process build output to (current-build-output-port).</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-03-19 21:44:36 +0100'>2021-03-19</span></td><td><a href='/guix/commit/build-aux/build-self.scm?id=ef2b9322fae1d03bf639924d12214b0f58c11054'>build-self: Silent Guile warnings while computing the derivation.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-02-04 09:23:39 +0100'>2021-02-04</span></td><td><a href='/guix/commit/build-aux/build-self.scm?id=316fc2acbb112bfa572ae30f95a93bcd56621234'>channels: Record 'guix' channel metadata in (guix config).</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-02-01 17:32:35 +0100'>2021-02-01</span></td><td><a href='/guix/commit/build-aux/build-self.scm?id=aedbc5ff32a62f45aeed74c6833399a6cf2c22dc'>guix package: Add '--export-channels'.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>