"Error: Unable to locate installed Perl libraries or Perl source code.

It is recommended that you install perl in a standard location before
building extensions. Some precompiled versions of perl do not contain
these header files, so you cannot build extensions. In such a case,
please build and install your perl from a fresh perl distribution. It
usually solves this kind of problem.

(You get this message, because MakeMaker could not find "/System/Library/Perl/5.8.1/darwin-thread-multi-2level/CORE/perl.h")
    -- NOT OK
Running make test
  Can't test without successful make
Running make install
  make had returned bad status, install seems impossible

cpan>"