I suspect it's a Math::BigInt/BigFloat bug

My suspicion was correct.
I dug into it a bit, and came up with this Math::BigInt PR, though I don't know if that's the optimal fix.
As mentioned in that PR, I subsequently noticed that there did already exist other builds of perl where ivsize=4 and nvtype was __float128, and that they were also striking the same Math::BigInt test failures as I was seeing.
(For example, https://www.cpantesters.org/cpan/report/2737c762-6c8c-1014-a5db-5bbf06c191b3 )

There has been no response to that PR yet. I'll file an Issue against perl5 itself if there has been no response to it by the end of next week.

Cheers,
Rob

In reply to Re^3: How to build perl-5.32.0 (or later) with ivsize of 4 on Ubuntu-20.04 ? by syphilis
in thread How to build perl-5.32.0 (or later) with ivsize of 4 on Ubuntu-20.04 ? by syphilis

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.