=item nowarnings

Warnings about modules where we can't find their META.yml or Makefile.PL, and
so can't divine their pre-requisites, will be suppressed;

=item fatalerrors

Failure to get a module's dependencies will be a fatal error
instead of merely emitting a warning;

=item perl

Use this version of perl to figure out what's in core.  If not
specified, it defaults to 5.005.  Three part version numbers
(eg 5.8.8) are supported but discouraged.

=item 02packages

The location of CPAN.pm's C<02packages.details.txt.gz> file as a
local filename, with either a relative or an absolute path.  If not
specified, it is fetched from a CPAN mirror instead.  The file is
fetched just once.

=item cachedir

A directory to use for caching.  It defaults to no caching.  Even if
caching is turned on, this is only for META.yml or Makefile.PL files.
02packages is not cached - if you want to read that from a local disk, see the
C<02packages> option.

=item maxdepth

Cuts off the dependency tree at the specified depth.  Your specified
module is at depth 0, your dependencies at depth 1, their dependencies
at depth 2, and so on.

=item usemakefilepl

If set to true, then for any module that doesn't have a META.yml,
try to use its Makefile.PL as well.  Note that this involves
downloading code from the Internet and running it.  This obviously
opens you up to all kinds of bad juju, hence why it is disabled
by default.

=item recommended

Adds recommended modules to the list of dependencies, if set to a true value.