In case the solution was not obvious to other onlookers. Here's the corrected version that I should have known to do in the first place. :/ 
#!/usr/bin/perl -Tw
# dead simple stupid script that echoes input
use CGI;
use Modern::Perl 2011;

my $head ='<!DOCTYPE html><head></head><body>
<br />
<form method="post" action="/valid-form.cgi">
';
my $form ='    <label for="input">Input: </label><input type="text" na
+me="input" value="" />
    <input type="submit" value="Post Input" />
';
my $foot ='
</form></body></html>';
print "content-type:text/html; charset=utf-8\n\n";
print $head;
print $form;
my $query = CGI->new;
my $input = $query->param('input');
if (!$input) {
    print "<br />No input";
}else{
    print "<br />$input";
}    
print $foot;

[download]
Take note of the additional my

Best wishes.

--Chris out...

#!/usr/bin/perl -Tw
use perl::always;
my $perl_version = (5.12.5);
print $perl_version;

In reply to Re^3: Why does Modern::Perl hate CGI.pm || my simple form? by taint
in thread Why does Modern::Perl hate CGI.pm || my simple form? by taint

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.