--- AnyEvent/constants.pl.PL	2012/03/27 23:47:57	1.11
+++ AnyEvent/constants.pl.PL	2012/09/22 00:22:59	1.12
@@ -10,7 +10,7 @@
 BEGIN { eval "use POSIX  ()" }
 
 open my $fh, ">lib/AnyEvent/constants.pl"
-   or die "lib/AnyEvent/constants.pl: $_[0]\n";
+   or die "lib/AnyEvent/constants.pl: $!\n";
 
 my $oldstdout = select $fh;