Don’t use stuff like my_die, which will not be respected by loaded modules. Don’t roll your own die handler.

Do use CGI::Carp. In development, the easiest thing to do is use CGI::Carp qw( fatalsToBrowser );. Once you are in production on an errorlog-challenged server, you do what the module’s POD says:

BEGIN {
    use CGI::Carp qw( carpout );
    my $logfile = '/path/to/cgi-name.log';
    open my $logfh, '>>', $logfile
        or die "Unable to open $logfile: $!\n";
    carpout $logfh;
}
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Makeshifts last the longest.