[I should check some of my own modules to make sure that this doesn't
happen to me, too...]
15 of the tests in t/02zlib.t fail when $ENV{PERL5OPT} =~
m/-MCarp=verbose/ and pass when it's removed. You may want to "local
$Carp::Verbose = 0;" near the beginning of that file, or skip the tests
in question when $Carp::Verbose == 1.