Search the path for krb5-config if the prefix wasn't specified.
--- openssh-3.8p1/configure.ac	2004-02-26 21:17:12.000000000 -0500
+++ openssh-3.8p1/configure.ac	2004-02-26 21:17:06.000000000 -0500
@@ -2077,8 +2077,10 @@
 		KRB5_MSG="yes"
 
 		AC_MSG_CHECKING(for krb5-config)
-		if test -x  $KRB5ROOT/bin/krb5-config ; then
-			KRB5CONF=$KRB5ROOT/bin/krb5-config
+		AC_PATH_PROG([KRB5CONF],[krb5-config],
+			     [$KRB5ROOT/bin/krb5-config],
+			     [$KRB5ROOT/bin:$PATH])
+		if test -x $KRB5CONF ; then
 			AC_MSG_RESULT($KRB5CONF)
 
 			AC_MSG_CHECKING(for gssapi support)