qcache: work around missing d_type/DT_DIR

--- qcache.c
+++ qcache.c
@@ -750,13 +750,21 @@
 
 		xasprintf(&catpath, "%s/dep/%s", portedb, data->overlay);
 		dir = opendir(catpath);
-		while ((de = readdir(dir)))
+		while ((de = readdir(dir))) {
+#ifndef DT_DIR
+			struct stat s;
+			if (stat(de->d_name, &s))
+				continue;
+			if (S_ISDIR(s.st_mode) && de->d_name[0] != '.') {
+#else
 			if (de->d_type == DT_DIR && de->d_name[0] != '.') {
+#endif
 				bool ok;
 				allcats = add_set_unique(de->d_name, allcats, &ok);
 				if (ok)
 					++numcat;
 			}
+		}
 		closedir(dir);
 		free(catpath);