Hi,

the recent addition of multiple author lines to the stack.xml file in
the ROS stack is incompatible with the specification used in previous
versions of the rospkg library distributed with ROS Fuerte. This is
not a big issue on freshly installed ROS systems since there is a Debian
package for rospkg now. However, when installing rosdep using
easy_install or pip, it also pulls in rospkg, whether or not it has
been installed already using the Debian package.

Based on a few questions at answers.ros.org, it seems like this
change caused a lot of trouble. It looks like people followed the
install instructions from the wiki page and installed rosdep. At some
point, they updated ROS to the new version with the changes to
stack.xml. Without doing an additional easy_install or pip update or
removing rospkg from /usr/local/lib by hand, this results in a broken
ROS installation where even roscore doesn't work anymore.

While this update does fix some other problems related to the ROS
stack.xml file,
I really wonder if it was a good idea to make such a fundamental
change in a released and officially stable ROS distro. Maybe it's time
to branch off for Groovy?

Also, why does rosdep actually still depend on rospkg although it is
now installed through apt? I don't feel like it's good to have two
possibly conflicting versions of rospkg installed on my system.

Lorenz

-- 
Lorenz Mösenlechner            | moesenle@in.tum.de
Technische Universität München | Karlstraße 45
80335 München                  | Germany
http://ias.cs.tum.edu/         | Tel: +49 (89) 289-26910