smoketst@hairball.cup.hp.com $ more /tmp/mypatch 
Index: config/auto/arch.pm
===================================================================
--- config/auto/arch.pm (revision 38492)
+++ config/auto/arch.pm (working copy)
@@ -39,6 +39,7 @@
     $verbose and print "\n";
 
     my $archname = $conf->data->get('archname');
+    $archname =~ s|\.|_|g;
     my ( $cpuarch, $osname ) = split( /-/, $archname );
 
     if ($verbose) {