I'd be inclined to add a fatalsToBrowser call: For example something like

#!/usr/bin/env perl

use CGI::Carp qw(fatalsToBrowser);
use strict;
use warning;

exit;
[download]

yields

Status: 500
Content-type: text/html

<h1>Software error:</h1>
<pre>Can't locate warning.pm in @INC (you may need to install the warn
+ing module) (@INC contains: C:/Perl/perl/site/lib C:/Perl/perl
/vendor/lib C:/Perl/perl/lib .) at cgi_01.pl line 5.
BEGIN failed--compilation aborted at cgi_01.pl line 5.
</pre>
<p>
For help, please send mail to this site's webmaster, giving this error
+ message
and the time and date of the error.

</p>
[Thu Jun  8 13:07:59 2017] cgi_01.pl: Can't locate warning.pm in @INC 
+(you may need to install the warning module) (@INC contains:
C:/Perl/perl/site/lib C:/Perl/perl/vendor/lib C:/Perl/perl/lib .) at c
+gi_01.pl line 5.
[Thu Jun  8 13:07:59 2017] ncgi_01.pl: BEGIN failed--compilation abort
+ed at cgi_01.pl line 5.
[download]

Remember to remove the "use CGI::Carp qw(fatalsToBrowser);" before putting your code into production.