Rosanswers logo

When I run colcon build to generate a custom message on Dashing, I get the following error:

Starting >>> druai_msg
--- stderr: druai_msg                         
CMake Error at /opt/ros/dashing/share/rosidl_adapter/cmake/rosidl_adapt_interfaces.cmake:60 (message):
  execute_process(/usr/bin/python3 -m rosidl_adapter --package-name druai_msg
  returned error code 1:

  Traceback (most recent call last):

    File "/usr/lib/python3.6/runpy.py", line 193, in _run_module_as_main
      "__main__", mod_spec)
    File "/usr/lib/python3.6/runpy.py", line 85, in _run_code
      exec(code, run_globals)
    File "/opt/ros/dashing/lib/python3.6/site-packages/rosidl_adapter/__main__.py", line 19, in <module>
    File "/opt/ros/dashing/lib/python3.6/site-packages/rosidl_adapter/main.py", line 55, in main
      pathlib.Path(relative_path), output_dir)
    File "/opt/ros/dashing/lib/python3.6/site-packages/rosidl_adapter/__init__.py", line 20, in convert_to_idl
      package_dir, package_name, interface_file, output_dir / 'msg')
    File "/opt/ros/dashing/lib/python3.6/site-packages/rosidl_adapter/msg/__init__.py", line 28, in convert_msg_to_idl
      msg = parse_message_string(package_name, input_file.stem, content)
    File "/opt/ros/dashing/lib/python3.6/site-packages/rosidl_adapter/parser.py", line 522, in parse_message_string
      msg = MessageSpecification(pkg_name, msg_name, fields, constants)
    File "/opt/ros/dashing/lib/python3.6/site-packages/rosidl_adapter/parser.py", line 373, in __init__
      pkg_name + PACKAGE_NAME_MESSAGE_TYPE_SEPARATOR + msg_name)
    File "/opt/ros/dashing/lib/python3.6/site-packages/rosidl_adapter/parser.py", line 196, in __init__
      raise InvalidResourceName(self.type)

  rosidl_adapter.parser.InvalidResourceName: druai

Call Stack (most recent call first):
  /opt/ros/dashing/share/rosidl_cmake/cmake/rosidl_generate_interfaces.cmake:130 (rosidl_adapt_interfaces)
  CMakeLists.txt:24 (rosidl_generate_interfaces)

Failed   <<< druai_msg  [ Exited with code 1 ]


<package format="3">
  <description>Examples of custom message handling</description>
  <maintainer email="[email protected]">Tim Craig</maintainer>
  <license>Apache License 2.0</license>
  <author>Tim Craig</author>






cmake_minimum_required(VERSION 3.5)

# Default to C++14

  add_compile_options(-Wall -Wextra -Wpedantic)

find_package(ament_cmake REQUIRED)
#find_package(rclcpp REQUIRED)
#find_package(std_msgs REQUIRED)

#Needed to handle custom messages
find_package(builtin_interfaces REQUIRED)
find_package(rosidl_default_generators REQUIRED)

#set(FastRTPS_INCLUDE_DIR:PATH /opt/ros/dashing/include)

#Generate the include file and other support for the custom message
  DEPENDENCIES builtin_interfaces)


Message file druai.msg, not that it seems to get that far.

string banner
int32 count

I shifted my focus to ROS2 when Dashing was released. Seems to have installed correctly. I successfully built the standard examples. Successfully built and ran my own publisher-subscriber pair for standard messages. However, when I tried to do a custom message following this tutorial which is for Crystal, it failed. It appears that the FastRTPS include files and libraries are there in /opt/ros/dashing/.....

[Tutorial video](https://www.youtube.com/watch?v=nG3IOkEOPps)

When I searched, I found something similar on an earlier distro of ROS2, Bouncy, I think. It wasn't helpful solving this.

OS: Ubuntu MATE 18.04 Distro: Dashing VirtualBox virtual machine on Windows 10

Originally posted by Tim Craig on ROS Answers with karma: 16 on 2019-09-13

Post score: 0

Original comments

Comment by LeoE on 2019-09-13:
Can you provide more information? CMakeList, package.xml and so on

Comment by tfoote on 2019-09-13:
Please edit your question to add this content instead of stringing it out in comments. You can integrate it for easier reading with new viewers for future reference.

Comment by LeoE on 2019-09-13:
First of all, don't know, if it is a copy paste mistake, but there is a < missing in your package.xml at member_of_group. Now have you tried deleting your build (and install) folder and rebuilding? Is Our ros2 path sourced? And why do you have a dependency on "builtin_interfaces"? This is not a necessary package for your example, if I'm not mistaken.

Comment by Tim Craig on 2019-09-13:
Ok, the missing < in the package.xml was in the original. I moved the package to a pristine workspace and tried again. The error changed. I've updated the original question with the current error message and data. Appears to cause an error in the interface generation python code.


1 Answer 1


Rosanswers logo

The problem stemmed from my .msg file beginning with a lower case letter. Change it to a capital and everything worked. I've searched and can't find where the file name for a .msg file must begin with a capital. This did not seem to be a requirement in ROS1 although a lot of examples did it.

In any event, it would be nice if this was made clearer and the response to a lower case beginning letter wasn't the message generator python program crashing and a simple error message indicating that was generated instead.

Originally posted by Tim Craig with karma: 16 on 2019-09-14

This answer was ACCEPTED on the original site

Post score: 0

Original comments

Comment by gvdhoorn on 2019-09-15:\

In any event, it would be nice if this was made clearer and the response to a lower case beginning letter wasn't the message generator python program crashing and a simple error message indicating that was generated instead.

I sympathise with you in that it took time to figure this out, and that it was unexpected, but the best way to make sure this either gets fixed (so case of filename doesn't matter any more), it gets documented better or the code dealing with this gets fixed (if this was actually more of a bug) would be for you to report this as an issue on the appropriate repository.

ROS Answers is not an issue tracker, and answers like this have very little visibility -- when used for reporting these sort of things.

Comment by 130s on 2023-05-01:
Looks like it was ticketed :) https://github.com/ros2/rosidl/issues/414


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.