There is no macro named SIZEOF_SSIZE_T. Should use SIZEOF_SIZE_T instead.
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 079eebf..107ed29 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -3795,7 +3795,7 @@
 
 /* --- MBCS codecs for Windows -------------------------------------------- */
 
-#if SIZEOF_INT < SIZEOF_SSIZE_T
+#if SIZEOF_INT < SIZEOF_SIZE_T
 #define NEED_RETRY
 #endif