ExtUtils::Installed vs pminst vs?

[Minty]

For a given #! line (with @INC optionally altered, primarily to add
local/private libs) I want to find out what modules I have installed.

http://search.cpan.org/dist/pmtools/pminst will do it, but doesn't
seem very cross platform friendly.  I've not yet tested it, but I
can't see it working on windows.

http://search.cpan.org/perldoc?ExtUtils::Installed fails (for me) on
Debian based distros using apt rather than cpan for package managment
because Debian don't include the .packlist files afaik.  I think this
also fails for local/private libs that aren't managed via cpan package
toolsets?  eg, installed via a cvs/git/svn checkout.

Holy wars aside, is there a cross platform friendly way to get a list
of what modules I have available?