自定义接口build失败

守护最好的佩奇

我在复制粘贴提供的自定义接口，build后出现以下错误：

CMake Error at /opt/ros/dashing/share/rosidl_cmake/cmake/rosidl_generate_interfaces.cmake:240 (list):
  list index: 1 out of range (-1, 0)
Call Stack (most recent call first):
  CMakeLists.txt:35 (rosidl_generate_interfaces)


CMake Error at /opt/ros/dashing/share/rosidl_typesupport_c/cmake/rosidl_typesupport_c_generate_interfaces.cmake:50 (message):
  Target dependency
  '/topic_test/build/ros2_interfaces/rosidl_adapter/ros2_interfaces/msg/RobotPose.idl'
  does not exist
Call Stack (most recent call first):
  /opt/ros/dashing/share/ament_cmake_core/cmake/core/ament_execute_extensions.cmake:48 (include)
  /opt/ros/dashing/share/rosidl_cmake/cmake/rosidl_generate_interfaces.cmake:286 (ament_execute_extensions)
  CMakeLists.txt:35 (rosidl_generate_interfaces)


---
Failed   <<< ros2_interfaces [4.88s, exited with code 1]

然后我在社区搜索相关解决方案，将CMake.list中的代码修改为以下：

cmake_minimum_required(VERSION 3.5)
project(ros2_interfaces)

# 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(rosidl_default_generators REQUIRED)
# find_package(geometry_msgs REQUIRED)
find_package(rosidl_default_generators REQUIRED)

if(BUILD_TESTING)
  find_package(ament_lint_auto REQUIRED)
  # the following line skips the linter which checks for copyrights
  # uncomment the line when a copyright and license is not present in all source files
  #set(ament_cmake_copyright_FOUND TRUE)
  # the following line skips cpplint (only works in a git repo)
  # uncomment the line when this package is not in a git repo
  #set(ament_cmake_cpplint_FOUND TRUE)
  ament_lint_auto_find_test_dependencies()
endif()

# rosidl_generate_interfaces(${PROJECT_NAME}
#   "msg/RobotPose.msg"
#   "msg/RobotStatus.msg"
#   "srv/MoveRobot.srv"
#   # DEPENDENCIES geometry_msgs
# )

ament_package()

可以build成功，但是我在调用时，提示我以下报错

Traceback (most recent call last):
  File "/home/xh/桌面/topic_test/install/example_topic/lib/example_topic/example_interfaces_robot_02", line 11, in <module>
    load_entry_point('example-topic==0.0.0', 'console_scripts', 'example_interfaces_robot_02')()
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 480, in load_entry_point
    return get_distribution(dist).load_entry_point(group, name)
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2693, in load_entry_point
    return ep.load()
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2324, in load
    return self.resolve()
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2330, in resolve
    module = __import__(self.module_name, fromlist=['__name__'], level=0)
  File "/home/xh/桌面/topic_test/install/example_topic/lib/python3.6/site-packages/example_topic/example_robot.py", line 7, in <module>
    from ros2_interfaces.msg import RobotStatus
ModuleNotFoundError: No module named 'ros2_interfaces'

而且在install文件夹内并没有出现文中所述的C++和Python环境，想问小鱼这是什么原因。
我安装的Ros2版本是dashing桌面版本，Ubuntu系统是18.04

小鱼

@守护最好的佩奇估计和你的ROS版本有关系，18实在太老了，建议换新版本使用，差距还是挺大的

s212633

@守护最好的佩奇我也遇到了报错，你解决了么？我是ubuntu20.04+foxy

小鱼

@s212633 贴一下具体的错误和文件看看