In recent versions of Perl, warnings says:

NOTE: FATAL warnings should be used with care, particularly FATAL => 'all'.

Libraries using warnings::warn for custom warning categories generally don't expect warnings::warn to be fatal and can wind up in an unexpected state as a result. For XS modules issuing categorized warnings, such unanticipated exceptions could also expose memory leak bugs.

Moreover, the Perl interpreter itself has had serious bugs involving fatalized warnings. For a summary of resolved and unresolved problems as of January 2015, please see this perl5-porters post.

Sounds like you may have run into just such a bug, in fact your code looks quite similar to that in #123398. Although it looks like there's a patch for that issue, the general recommendation would be to not use FATAL => 'all', especially in light of the additional reasons to avoid it listed in the documentation. If you wanted to submit a bug via perlbug, I would suspect that because of the above it won't get a high priority unless you provide a patch or can show that it also causes a problem when warnings aren't fatalized.

In reply to Re: SIGSEGV instead of "Not a hash ref" in destructor w/ FATAL => all by Anonymous Monk
in thread SIGSEGV instead of "Not a hash ref" in destructor w/ FATAL => all by halfcountplus

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.