It was =head1 TITLE that I added, as you wrote, not =head TITLE as in the typo from my earlier reply (sorry for the typo).

A moment ago, as an experiment I tried changing the =head1 to =head ... and with that change, the podchecker definitely flagged an error, which didn't happen when I tried your suggestion before.
So that wasn't the issue. BUT as it happens, I did just now make a breakthrough, with something not related to POD content...

There appear two have been two issues contributing to my situation. One was the lack of a heading starter, as you pointed out. That appears to be the cause of the status=1 error exit. The other is that, on both of my systems, I was seeing no output because of the PERLDOC_PAGER=“less -+C -E” value that I was using. Because my POD text is so short... less than one page... the “-E” option was causing less to exit immediately (normal exit) after displaying the text. So there still appeared to be no output -- although looking more closely, the screen sometimes flickers slightly while the output appears and then disappears. In this case the exit status was normal 0 instead of 1.

So if I change PERLDOC_PAGER to just “less” then all works OK (!), as long as the =head1 element is in the POD.

On the question about error messages, part of my trouble was that there never were any error messages displayed in a usual way. But the perlpod exit status was different (1 before your fix, 0 after your fix despite still no visible output from the POD).

That said, I’m a bit surprised that this heading element is required. In the perlpod web page, when I read “You can simply type in your text without any markup whatsoever, and with just a blank line before and after,” apparently I took that too literally, or perhaps out of context. Looking at the page again, it still doesn’t look obvious to me that a heading paragraph is required to be present, from the description in that page. It’s also a bit odd that the podchecker indicated all was OK in my original file, despite lack of that element whose absence caused an error in perldoc.

As for the strace output: interesting as that was, it appears that the rt_sigaction call with EINVAL return was a red herring.

Thanks for the help!!