Perl 5.8.7 does not support shared sub refs and this test (which
worked prior to 5.8.7)  barfs like so:

Invalid value for shared scalar at /System/Library/Perl/5.8.6/Test/Builder.pm line 319.
WHOA!  Somehow you got a different number of results than tests ran!
This should never happen!  Please contact the author immediately!
END failed--call queue aborted.
t/ls.........dubious


And so until this is fixed in Perl, I have to stop doing this test!