Error when trying to create a custom service

[fabmene]

Bug report

Required Info:

• Operating System:
  • Ubuntu 18.04
• Installation type:
  • Binaries
• Version or commit hash:
  • Eloquent
• DDS implementation:
  • CycloneDDS
• Client library (if applicable):
  • rclcpp

Steps to reproduce issue

package.xml

<?xml version="1.0"?>
<?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
<package format="3">
  <name>my_pkg</name>
  <version>0.0.0</version>
  <description>TODO: Package description</description>
  <maintainer email="john.doe@xyz.org">john doe</maintainer>
  <license>TODO: License declaration</license>

  <buildtool_depend>ament_cmake</buildtool_depend>
  <depend>rmw_cyclonedds_cpp</depend>

  <!-- required for msg/srv gen -->
  <member_of_group>rosidl_interface_packages</member_of_group>

  <export>
    <build_type>ament_cmake</build_type>
  </export>
</package>

CMakeLists.txt

cmake_minimum_required(VERSION 3.5)
project(my_pkg)

# Default to C99
if(NOT CMAKE_C_STANDARD)
  set(CMAKE_C_STANDARD 99)
endif()

# Default to C++14
if(NOT CMAKE_CXX_STANDARD)
  set(CMAKE_CXX_STANDARD 14)
endif()

if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
  add_compile_options(-Wall -Wextra -Wpedantic)
endif()

# find dependencies
find_package(ament_cmake REQUIRED)
find_package(rclcpp REQUIRED)
find_package(rosidl_default_generators REQUIRED)

rosidl_generate_interfaces(${PROJECT_NAME}_srv
  "srv/MySrv.srv"
)

add_executable(my_node
  src/my_node.cpp)

rosidl_target_interfaces(my_node
  ${PROJECT_NAME}_srv "rosidl_typesupport_cpp")

ament_target_dependencies(my_node rclcpp)

install(TARGETS
  my_node
  ARCHIVE DESTINATION lib/${PROJECT_NAME}
  RUNTIME DESTINATION lib/${PROJECT_NAME}
  LIBRARY DESTINATION lib
)

ament_package()

srv/MySrv.srv

bool foo
---
int64 bar

src/my_node.cpp

#include <rclcpp/rclcpp.hpp>
#include "my_pkg/srv/my_srv.hpp"

class MyNode : public rclcpp ::Node
{

public:
  MyNode(const rclcpp::NodeOptions& options)
      : rclcpp::Node("my_node", rclcpp::NodeOptions(options)
                                    .start_parameter_event_publisher(false)
                                    .start_parameter_services(false))
  {
    mSrv = this->create_service<my_pkg::srv::MySrv>(
        "/foo", std::bind(&MyNode::execEvalCB, this,
                                          std::placeholders::_1, std::placeholders::_2));
  }

  void execEvalCB(const my_pkg::srv::MySrv::Request::SharedPtr pReq,
                                       const my_pkg::srv::MySrv::Response::SharedPtr pRes){}


  rclcpp::Service<my_pkg::srv::MySrv>::SharedPtr mSrv;
};

int main(int argc, char** argv)
{
  rclcpp::init(argc, argv);

  rclcpp::Node::SharedPtr node = std::make_shared<MyNode>(rclcpp::NodeOptions());
  rclcpp::spin(node);

  return 0;
}

Expected behavior

Service is offered

Actual behavior

Error thrown:

Failed to find library 'my_pkg__rosidl_typesupport_introspection_cpp'

>>> [rcutils|error_handling.c:107] rcutils_set_error_state()
This error state is being overwritten:

  'service type support not from this implementation, at /tmp/binarydeb/ros-eloquent-rmw-cyclonedds-cpp-0.4.4/src/rmw_node.cpp:2302'

with this new error message:

  'type_support is null, at /tmp/binarydeb/ros-eloquent-rmw-cyclonedds-cpp-0.4.4/src/rmw_node.cpp:2320'

rcutils_reset_error() should be called after error handling to avoid this.
<<<
terminate called after throwing an instance of 'rclcpp::exceptions::RCLError'
  what():  could not create service: type_support is null, at /tmp/binarydeb/ros-eloquent-rmw-cyclonedds-cpp-0.4.4/src/rmw_node.cpp:2320, at /tmp/binarydeb/ros-eloquent-rcl-0.8.4/src/rcl/service.c:179

[dirk-thomas]

Please share the complete code of a reproducible example (including the package.xml file as well as the complete CMake code).

Note: you might want to use the typedefs for the request / response instead: e.g. my_pkg::srv::MySr::Request::SharedPtr.

[fabmene]

I updated the OP with all information.

[fabmene]

Testing this issue further, I see the same problem with all other non-fastrtps middle-wares as well, meaning this is likely not a pure cyclone-dds issue.

Furthermore, once I rebuild my workspace after switching around between middlewares, even FastRTPS fails to support the custom service.

Failed to find library 'my_pkg__rosidl_typesupport_fastrtps_cpp'
terminate called after throwing an instance of 'rclcpp::exceptions::RCLError'
  what():  could not create service: type support not from this implementation, at /tmp/binarydeb/ros-eloquent-rmw-fastrtps-cpp-0.8.1/src/rmw_service.cpp:95, at /tmp/binarydeb/ros-eloquent-rcl-0.8.4/src/rcl/service.c:179

Inbetween a successful launch with FastRTPS and the above error, the only things I did was starting my node, setting RMW_IMPLEMENTATION and clean-building my workspace (which only contains the one package listed in the OP).

I understand this is likely not the correct location to discuss this issue, but I'm not sure where it would belong either.

[dirk-thomas]

Atm the generated library for the interfaces must have the basename ${PROJECT_NAME}.

You have to options:

• either rename your interface target to just ${PROJECT_NAME}:

  rosidl_generate_interfaces(${PROJECT_NAME} "srv/MySrv.srv")
  rosidl_target_interfaces(my_node ${PROJECT_NAME} "rosidl_typesupport_cpp")
  

• or explicitly set the library name:

  rosidl_generate_interfaces(${PROJECT_NAME}_srv "srv/MySrv.srv" LIBRARY_NAME ${PROJECT_NAME})
  

[fabmene]

Thank you for your answer, this way it indeed works for middlewares other than FastRTPS. Still curious that it worked fine with the latter.