http://lists.research.att.com/pipermail/ast-developers/2014q1/003806.html

--- a/src/cmd/ksh93/sh/init.c
+++ b/src/cmd/ksh93/sh/init.c
@@ -1933,6 +1933,11 @@ static void env_init(Shell_t *shp)
 		*dp++ = 0;
 		if(mp = dtmatch(shp->var_base,cp))
 		{
+                        if(strcmp(cp,VERSIONNOD->nvname)==0)
+                        {
+                                dp[-1] = '=';
+                                continue;
+                        }
 			mp->nvenv = (char*)cp;
 			dp[-1] = '=';
 		}