The following commands attempts to reinstall, I just want to download w/o installing. I'm usnig Ubuntu.
cpanm Test::Fatal --save-dists saved
You could use cpanget (part of cpanspec).Or, cpan -g module module.
While I hail from a RH platform, ultimately both command come from the CPAN archive and "cpan" in particular - from the CPAN distribution, should be totally platform agnostic, and comes to a little more of
use App::Cpan; my $rc = App::Cpan->run( @ARGV ); exit $rc;
You can try
cpanm --test-only --notest Test::Fatal
and then look into '~/.cpanm/latest-build/', here should be all sources used in last build process.