Check that default_path_patterns is not None before using in "build_path"
@@ -1167,6 +1167,7 @@ class BIDSLayout(object):
for c in l.config.values():
if c in seen_configs:
continue
+ if c.default_path_patterns is not None:
path_patterns.extend(c.default_path_patterns)
seen_configs.add(c)
