action_msgs is a magic dependency for new action interfaces #75
Description
Bug report
This is not a bug in the sense that it is broken, rather it is a very awkward thing to debug because it is surprising behaviour with very difficult to grokk error messages when the behaviour isn't followed.
- Operating System:
- Ubuntu 18.04
- Installation type:
- Binaries
- Version or commit hash:
- crystal
- DDS implementation:
- Default
- Client library (if applicable):
- N/A
Steps to reproduce issue & Actual Behaviour
- Create your first action in a typical ros interfaces package
- Compile
[ 11%] Generating C introspection for ROS interfaces
/usr/bin/python3 /opt/ros/crystal/lib/rosidl_typesupport_introspection_c/rosidl_typesupport_introspection_c --generator-arguments-file /mnt/mervin/workspaces/crystal/muppet/build/muppet_msgs/rosidl_typesupport_introspection_c__arguments.json
Service interface 'unique_identifier_msgs/UUID' contains an unknown field type: unique_identifier_msgs/UUID action_goal_id
CMakeFiles/muppet_msgs__rosidl_typesupport_introspection_c.dir/build.make:150: recipe for target 'rosidl_typesupport_introspection_c/muppet_msgs/msg/can_frame__rosidl_typesupport_introspection_c.h' failed
make[2]: *** [rosidl_typesupport_introspection_c/muppet_msgs/msg/can_frame__rosidl_typesupport_introspection_c.h] Error 1
make[2]: Leaving directory '/mnt/mervin/workspaces/crystal/muppet/build/muppet_msgs'
make[2]: *** Deleting file 'rosidl_typesupport_introspection_c/muppet_msgs/msg/can_frame__rosidl_typesupport_introspection_c.h'
CMakeFiles/Makefile2:1689: recipe for target 'CMakeFiles/muppet_msgs__rosidl_typesupport_introspection_c.dir/all' failed
make[1]: Leaving directory '/mnt/mervin/workspaces/crystal/muppet/build/muppet_msgs'
Makefile:140: recipe for target 'all' failed
make[1]: *** [CMakeFiles/muppet_msgs__rosidl_typesupport_introspection_c.dir/all] Error 2
make: Leaving directory '/mnt/mervin/workspaces/crystal/muppet/build/muppet_msgs'
make: *** [all] Error 2
- Be baffled
- After much digging, guess that
action_msgsis needed in theDEPENDENCIESof therosidl_generate_interfacescall after seeing the official example (thanks for that!).
Expected behavior
The solution described above is surprising - typically only direct dependencies of variables in messages or services need to be described there. Two ideas:
- Find a way to bring in
action_msgsautomatically if any actions are to be compiled (if possible) - Find a way to provide an error message that recognises the problem and can give a hint of what to do in this situation.