Done, and also received feedback already! Here's the bug report: https://rt.cpan.org/Ticket/Display.html?id=39323

And here's the solution I was seeking, based on demo/demo_errors.pl: 

use strict;
use Data::Dumper;
use Parse::RecDescent;

# Simple Lisp S-expressions (as an example)
my $grammar = q#
    start: expression(s?)
         | { die join("\n", map { $_->[0] } @{ $thisparser->{errors} }
+)."\n" }

    expression: /\w+/ 
              | '(' expression(s?) ')'
                { $item[2] }
              | <error>
#;

my $p = Parse::RecDescent->new($grammar);
# This will die if there is an error.
print Dumper($p->start('(foo (bar))'));

# Like so:
$p->start('(foo');

[download]

--
say "Just Another Perl Hacker";

In reply to Re^5: How to grab Parse::RecDescent error output in a variable? by vrk
in thread How to grab Parse::RecDescent error output in a variable? by vrk

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.