tf2 in groovy defines unnecessary CATKIN_DEPENDS (e.g. on rospy)

[tkruse]

I checked the .pc files generated for a fresh groovy source install.

I get:

$ find devel_isolated/ -name *.pc | xargs grep Req | grep rospy
devel_isolated/diagnostic_aggregator/lib/pkgconfig/diagnostic_aggregator.pc:Requires: diagnostic_msgs pluginlib roscpp rospy xmlrpcpp
devel_isolated/tf2_ros/lib/pkgconfig/tf2_ros.pc:Requires: actionlib actionlib_msgs geometry_msgs message_filters roscpp rosgraph rospy tf2 tf2_msgs
devel_isolated/tf2/lib/pkgconfig/tf2.pc:Requires: geometry_msgs tf2_msgs rospy roscpp
devel_isolated/interactive_markers/lib/pkgconfig/interactive_markers.pc:Requires: roscpp rosconsole rospy tf visualization_msgs

I am not 110% sure, but I believe there is no need ever for a library to know of rospy to build against tf2, diagnostic_aggregator or interactive_markers. So it seems to me those have flawed CMakeLists.txt

Possibly more exported dependencies than rospy are superfluous there (e.g. actionlib stuff).

Also see:
http://answers.ros.org/question/58498/what-is-the-purpose-of-catkin_depends/

I am too lazy to create individual tickets for each of the packages above, especially since I might be wrong.

[tfoote]

fixed in groovy 6c8ea39

[tkruse]

I also miss boost as DEPENDS, used in https://github.com/ros/geometry_experimental/blob/hydro-devel/tf2/include/tf2/buffer_core.h
On the other hand, I am not sure whether console_bridge should be exported as dependency, given it's not used in the public headers.

I could go on.

E.g.
tf2_bullet: misses geometry_msgs and tf2 as exports
tf2_geometry_msgs: tf2_ros is exported but not used
tf2_kdl: misses geometry_msgs (both as find_package as well as in catkin_depends), and tf2 as catkin_depends

Correct me if I am wrong, but a review process for the catkin_package macro should go like this:

1. Check the package author did not do something unorthodox and installs headers from somewhere else than /include//*.h (if he did, this should probably in itself be a style ticket, in conventional packages)
2. Look what is used in the /include//*.h files (and only those)
3. Make sure all packages mentioned there are declared in catkin_package as DEPENDS or CATKIN_DEPENDS
4. Anything in catkin_package not mentioned in any of the headers should go, unless it's something exceptional (genmsg, not sure what else would count)

The more packages get this worng, the more people will be confused and annoyed about catkin. I think except for packages catkinized by maybe Dirk or Vincent, most packages get the DEPENDS and CATKIN_DEPENDS wrong. Maybe that is a hint that those keywords are not helpful and self-explaining, but confusing?

[tkruse]

Note I am not just talking about the tf2 packages here, I am talking about hydro in general. Sampling over at a few catkin packages in hydro, I see many packages flawed that way, and that is a major problem in the general introduction of catkin.