check.pl

use warnings;

CHECK {
    warn "CALL check"
}

deparsed-main.pl

use warnings;
BEGIN {${^WARNING_BITS} = "\x55\x55\x55\x55\x55\x55\x55\x55\x55\x55\x55\x51\x55\x55\x55\x55\x55\x55"}
do './check.pl';

main-numeric.pl

use warnings;

no warnings qw(numeric);
do './numeric.pl';
# Argument "2:" isn't numeric in addition (+) at ./numeric.pl line 3.
# 5 at ./numeric.pl line 4.

main.pl

use warnings;

no warnings qw(void);
do './check.pl';
# => Too late to run CHECK block at ./check.pl line 6.

numeric.pl

use warnings;

my $a = '2:' + 3;
warn $a;