I'll try to clarify :)

I usually upgrade AS perl builds without rebuilding the packages that don't come with it. That's worked reliably since 5.8.0. However, when I first installed 5.8.7/AS813, the installed failed right towards the end. It didn't tell me what failed, but I am guessing that it was generating the HTMLised POD. It insisted on backing the install off, but left the previous 5.8.6 build broken to the point where perl simply wouldn't start. AS support suggested that I should always uninstall the previous build, (leaving the non-AS packages in place), before installng a new AS build. I attempted this with AS813 but it still failed at the end in the same way.

I reinstalled 5.8.6 over the top of what was left and things seemed okay. A few days later AS815 became available so I got that, uninstalled 5.8.6, again leaving the non distribution packages in place and attempted the AS815 install. It went through cleanly.

However, there were various instances of previously working code doing strange things--mostly resulting in a "free to wrong pool". I've seen this message a lot in the past with code that used threads badly, but these were simple non-threaded programs. The latest of which is the subject of the OP. This a highly cut-down version of a program that has worked fine since 5.8.3 and through several upgrades of GD, that suddenly started working one time but not the next. As you can see from the OP and zentara's post above, it is really very obscure when you can call a sub successfully once, or even twice to do exactly the same processing, from different places in the code--but not twice from the same place!

So, given the immediate preceding history of failed installed and broken restorations, I was unable in good conscience to 'point the finger' at 5.8.7. Hence my need to re-build everything clean to be sure.

My fear is, that as I have now built all those packages in conjunction with 5.8.7, whatever malady is the root cause of the segfault may now be compiled into, (via errors in the Perl header files?), all the (XS components of) packages that I built in conjunction with it.

It may be that the problem was unrelated to the header files in any way, but with perl 5.8.7 delta saying

There has been a fair amount of refactoring of the C source code,

can I be sure?

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal?
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

In reply to Re^4: Segfault on second (identical) call to a sub by BrowserUk
in thread Segfault on second (identical) call to a sub by BrowserUk

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.