On Mon, Nov 21, 2011 at 4:22 AM, Dirk Thomas <mail@dirk-thomas.net> wrote:

Is it so awful if the user ends up with redundant packages installed?

The point is it might not be possible to install one of the dependencies on some platforms.
I.e. when building the ROS GUI we need either PyQt with SIP or PySide with Shiboken.
But on "older" Ubuntu versions (before natty?) Shiboken bindings will not compile correctly.
So specifying both may lead to errors on some platforms and it would not be clear to the user that those can be ignored in this special case.

rosdep.yaml files can specify different packages for different operating system versions. Seems like you could use that to declare a "python-qt-binding" rosdep which installs PyQt on pre-natty Ubuntu and PySide on Natty and beyond.