--- ./src/editfns.c.orig	2020-07-29 23:40:42.000000000 +0200
+++ ./src/editfns.c	2020-09-14 21:36:04.890630177 +0200
@@ -1250,7 +1250,7 @@
   if (!pw)
     return Qnil;
 
-  p = USER_FULL_NAME;
+  p = "unknown";
   /* Chop off everything after the first comma. */
   q = strchr (p, ',');
   full = make_string (p, q ? q - p : strlen (p));