--- comgr/src/comgr-env.h.orig	2023-06-07 02:39:28.039489253 +0200
+++ comgr/src/comgr-env.h	2023-06-07 02:39:58.502264137 +0200
@@ -38,6 +38,7 @@
 
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/None.h"
 
 namespace COMGR {
 namespace env {