Very nice. As always, it should be noted that relying on the stringification of references may lead to surprises if overloading has been brought into play. Also, with a more specific pattern: 
package WWW::Mechanize::NoRefs;
use base 'WWW::Mechanize';

my $rx = qr/(
    (?: [A-Za-z]\w* (?: :: [A-Za-z]\w* )* = )?
    (?: SCALAR | ARRAY | HASH | CODE | REF | GLOB | LVALUE )
    \( 0x [a-fA-F0-9]+ \)
)/x;

sub content {
    my $self    = shift;
    my $content = $self->SUPER::content;
    if ($content =~ $rx) {
        require Carp;
        Carp::carp("Possible stringified reference ($1) found in conte
+nt");
    }
    return $content;
}

1;

[download]

Makeshifts last the longest.

In reply to Re: Detecting stringified references with WWW::Mechanize by Aristotle
in thread Detecting stringified references with WWW::Mechanize by Ovid

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.