Index: b/test/formats/test_id3.py
===================================================================
--- a/test/formats/test_id3.py
+++ b/test/formats/test_id3.py
@@ -266,5 +266,5 @@
         def test_rename_txxx_tags(self):
             file_path = os.path.join('test', 'data', 'test-id3-rename-tags.mp3')
-            filename = self.copy_file_tmp(file_path, 'mp3')
+            filename = self.copy_file_tmp(file_path, '.mp3')
             raw_metadata = load_raw(filename)
             self.assertIn('TXXX:Artists', raw_metadata)
x/'>guix</a></td><td class='form'><form method='get'>
<input type='hidden' name='id' value='8a442e5db2989df6283b323fc8176df75972bab2'/><select name='h' onchange='this.form.submit();'>
<option value='koszko' selected='selected'>koszko</option>
<option value='koszko-scripts'>koszko-scripts</option>
</select> <input type='submit' value='switch'/></form></td></tr>
<tr><td class='sub'>Wojtek's customized Guix</td><td class='sub right'>