I did it. I finally killed that damned threading test in Test::More. is_deeply_fail.t will no longer run unless AUTHOR_TESTING is set.
For those who don't know, that test would tickle intermittent threading bugs in certain vendor supplied versions of perl. The 5.8.6 OS X ships with and most Redhat derivatives are vulnerable, but it would only fail about one in a hundred times. I don't know what the problem is, I suspect it's from vendors pulling in bleadperl patches but I haven't confirmed. Nobody's put the time into it to find out.
Since there's nothing I can do about it, and it was just holding up CPAN installations, I turned the test off. Done.