. . . . .
CHORNY/Apache-Session-1.88.zip
  :unwrapped NO -- unzip failed

My CPAN::Config.pm fragment:-
. . . . .
  'show_upload_date' => q[0],
  'term_ornaments' => q[1],
  'unzip' => [q[/usr/local/bin/unzip]],
  'bzip2' => q[/usr/bin/bzip2],
  'gzip' => q[/usr/bin/gzip],
  'zip' => [q[/usr/local/bin/zip]],
  'urllist' => [q[file:/Usb/t/cpan_mirror/]],
. . . . .
ls -l /usr/local/bin/zip*
-r-xr-xr-x 1 root wheel 179672 18Sep2009 /usr/local/bin/zip