#!/usr/bin/perl
#
use warnings; use strict; use 5.008;
sub monk($) {}
sub go() { mink(123); }
BEGIN { print "$_\n" for grep { /^m/ } sort keys %main:: }
go();
__END__
main::
mink
monk
Undefined subroutine &main::mink called at sub.pl line 5.

##</code><code>##

#!/usr/bin/perl
#
use warnings; use strict; use 5.008;
sub mink;      # sub mink still undefined, but typeglob allocated.
sub monk($) {}
sub go() { mink(123); }
BEGIN { print "$_\n" for grep { /^m/ } sort keys %main:: }
go();
__END__
main::
mink
monk
Undefined subroutine &main::mink called at sub.pl line 6.

##</code><code>##

use strict;
$SIG{CHLD} = \&mywait; # value in the %SIG hash is an empty code ref