[ros-users] resolving open REP-0122 issues

[Lorenz Mösenlechner]

On Wed, Jul 25, 2012 at 1:00 PM, Jack O'Quin <jack.oquin at gmail.com> wrote:
> On Wed, Jul 25, 2012 at 4:03 AM, Lorenz Mösenlechner <moesenle at in.tum.de> wrote:
>> In addition, I don't think that it is possible to convert all ros
>> packages to catkin. Catkin is all about building but what about the
>> packages that don't contain code? There are a lot of packages out
>> there that contain only launch files and dependencies to build
>> everything that is necessary to start these launch files. The most
>> prominent examples would be pr2_bringup or pr2_gazebo. I don't really
>> see how that is possible in a catkinized world.
>
> Those packages will have to be converted, too, because the launch
> scripts will need to be installed somewhere. In that sense, XML files
> *are* code.

That is true.  But it's not about installing launch files but about
managing dependencies and building everything that is necessary.

At the moment, I guess most people have a lot of packages in a
repository, not necessarily organized in stacks and possibly with some
packages being broken. In particular, some of the packages are there
only for specifying dependencies that are required to run something,
e.g. for bringing up the robot. With rosmake, getting everything built
that is required for running the robot is easy. With catkin, I would
either need to build everything in that repo which might not work due
to broken packages  or I would need to create something like a build
workspace that symlinks only the packages I want to build. Both
solutions would require some manual work.

I think one reason for the great success of ros was that it made it
really easy to use other people's code and get the dependencies
resolved with just one call to rosmake. With catkin, the user needs to
be more organized and building something just requires more knowledge
and more work.

Lorenz



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