ModuleNotFoundError：尽管在 carla-ros-bridge wsl-2 中使用 colcon build 时安装了 empy，但没有名为“em”的模块

Question

在 wsl-2 的 carla-ros-bridge 根目录中运行 colcon build 时， python 抛出ModuleNotFoundError: No module named 'em' 。 具体来说，它会产生这个 output：

--- stderr: carla_ros_scenario_runner_types
CMake Error at /opt/ros/foxy/share/rosidl_adapter/cmake/rosidl_adapt_interfaces.cmake:60 (message):
  execute_process(/home/jakob/miniconda3/bin/python3 -m rosidl_adapter
  --package-name carla_ros_scenario_runner_types --arguments-file
  /home/jakob/carla-ros-bridge/build/carla_ros_scenario_runner_types/rosidl_adapter__arguments__carla_ros_scenario_runner_types.json
  --output-dir
  /home/jakob/carla-ros-bridge/build/carla_ros_scenario_runner_types/rosidl_adapter/carla_ros_scenario_runner_types
  --output-file
  /home/jakob/carla-ros-bridge/build/carla_ros_scenario_runner_types/rosidl_adapter/carla_ros_scenario_runner_types.idls)
  returned error code 1:

  Traceback (most recent call last):

    File "/home/jakob/miniconda3/lib/python3.10/runpy.py", line 196, in _run_module_as_main
      return _run_code(code, main_globals, None,
    File "/home/jakob/miniconda3/lib/python3.10/runpy.py", line 86, in _run_code
      exec(code, run_globals)
    File "/opt/ros/foxy/lib/python3.8/site-packages/rosidl_adapter/__main__.py", line 19, in <module>
      sys.exit(main())
    File "/opt/ros/foxy/lib/python3.8/site-packages/rosidl_adapter/main.py", line 53, in main
      abs_idl_file = convert_to_idl(
    File "/opt/ros/foxy/lib/python3.8/site-packages/rosidl_adapter/__init__.py", line 18, in convert_to_idl
      from rosidl_adapter.msg import convert_msg_to_idl
    File "/opt/ros/foxy/lib/python3.8/site-packages/rosidl_adapter/msg/__init__.py", line 16, in <module>
      from rosidl_adapter.resource import expand_template
    File "/opt/ros/foxy/lib/python3.8/site-packages/rosidl_adapter/resource/__init__.py", line 19, in <module>
      import em

  ModuleNotFoundError: No module named 'em'

Call Stack (most recent call first):
  /opt/ros/foxy/share/rosidl_cmake/cmake/rosidl_generate_interfaces.cmake:130 (rosidl_adapt_interfaces)
  CMakeLists.txt:39 (rosidl_generate_interfaces)


---

我在别处读到这个错误是由 package “empy” 丢失引起的，所以我运行pip3 install empy和pip install empy ，都产生了 output: Defaulting Defaulting to user installation because normal site-packages is not writeable Requirement already satisfied: empy in /home/jakob/.local/lib/python3.8/site-packages (3.3.4)

python -V 输出：Python 2.7.18 python3 -V 输出：Python 3.8.10

我没有办法解决这个问题

我试过： - 安装 em 并再次运行构建（抛出不同的错误消息） - 重新安装 empy （无更改） - 删除 carla-ros-bridge 根目录并再次克隆它

Answer 1

我发现了错误。 如果查看 Traceback，您会发现 Python 使用两个不同的路径指向两个不同的版本。 特别/home/jakob/miniconda3/lib/python3.10/和/opt/ros/foxy/lib/python3.8/site-packages/ 。 这是因为我在与 carla-ros-bridge 不同的 miniconda 环境中构建 ros foxy。 修复是删除 carla ros 桥并下载，然后在使用 python 3.8 的环境中再次构建它。