sudo port upgrade all

[Joshua Root]

Neil wrote:
> I'd really like to see a pretend-mode, where MacPorts shows me what it
> would do, without doing it.  Often times I'm trying to track down what
> port is causing another port to be installed, and my current method
> (guessing, installing, uninstalling, repeat) is not optimal, I don't
> think...

That's <http://trac.macports.org/ticket/11892>. Or for now there's this
script:
<http://svn.macports.org/repository/macports/contrib/port-rdeps/port-rdeps>

- Josh