CPAN tester imacat re-tested ExtUtils::ModuleMaker (repeatedly! and on multiple OSes! valiant work) and sent me this message:
I tested it again and could not reproduce the same failure. However I found that error is caused by the incompatibility from the just-tested IO 1.22 with Perl itself boundled with IO 1.21. Due to some test suite problem it keeps loading the just-tested IO 1.22 from @INC and caused incompatibility problem with Perl itself. I have submit several OK reports on ExtUtils-ModuleMaker, and forwarded this message to Robert Rothenberg, the author of CPAN::YACSmoke.
Jim Keenan