launch启动报错

bstd321

标题：launch 启动报错 Caught multiple exceptions when trying to load file of format [py]（ROS2 HUMBLE）

提问模板（建议直接复制粘贴）：

背景(可选)：

此为练习程序，我写了一个robot_tracker包用来读取robot_sensor的数据并滤波，编译能够通过，但是启动时报了以下错误

问题描述：

[在这里详细描述您遇到的问题。请确保您提供了足够的背景信息，以便其他人能够理解您的问题。]

具体细节和上下文：

launch 启动报错 Caught multiple exceptions when trying to load file of format [py]（ROS2 HUMBLE）
使用了VsCode的Ros插件启动launch文件
启动运行之前使用了以下脚本进行工程的构建

if [ "$SHELL" = "/bin/zsh" ]; then
    echo "source /opt/ros/humble/setup.zsh"
    source /opt/ros/humble/setup.zsh
elif [ "$SHELL" = "/bin/bash" ]; then
    echo "source /opt/ros/humble/setup.bash"
    source /opt/ros/humble/setup.bash
else
    echo "source /opt/ros/humble/setup.sh"
    source /opt/ros/humble/setup.sh
fi

# 清理robot_tracker的旧文件
echo "清理robot_tracker的旧文件"
rm -rf build/robot_tracker install/robot_tracker
rm -rf src/robot_tracker/launch/__pycache__
mkdir -p build/robot_tracker install/robot_tracker

# 清理robot_interfaces的旧文件
echo "清理robot_interfaces的旧文件"
rm -rf build/robot_interfaces install/robot_interfaces
mkdir -p build/robot_interfaces install/robot_interfaces

# 清理robot_sensor的旧文件
echo "清理robot_sensor的旧文件"
rm -rf build/robot_sensor install/robot_sensor
mkdir -p build/robot_sensor install/robot_sensor

# 构建 robot_interfaces
echo "构建 robot_interfaces..."
colcon build --packages-select robot_interfaces

if [ "$SHELL" = "/bin/zsh" ]; then
    echo ". install/setup.zsh"
    . install/setup.zsh
elif [ "$SHELL" = "/bin/bash" ]; then
    echo ". install/setup.bash"
    . install/setup.bash
else
    echo ". install/setup.sh"
    . install/setup.sh
fi

# 构建 robot_sensor
echo "构建 robot_sensor..."g
colcon build --packages-select robot_sensor --symlink-install --event-handlers console_cohesion+ --cmake-args -DCMAKE_BUILD_TYPE=Debug

if [ "$SHELL" = "/bin/zsh" ]; then
    echo ". install/setup.zsh"
    . install/setup.zsh
elif [ "$SHELL" = "/bin/bash" ]; then
    echo ". install/setup.bash"
    . install/setup.bash
else
    echo ". install/setup.sh"
    . install/setup.sh
fi

# 构建 robot_tracker
echo "构建 robot_tracker..."g
colcon build --packages-select robot_tracker --symlink-install --event-handlers console_cohesion+ --cmake-args -DCMAKE_BUILD_TYPE=Debug

if [ "$SHELL" = "/bin/zsh" ]; then
    echo ". install/setup.zsh"
    . install/setup.zsh
elif [ "$SHELL" = "/bin/bash" ]; then
    echo ". install/setup.bash"
    . install/setup.bash
else
    echo ". install/setup.sh"
    . install/setup.sh
fi

echo "构建完成。"

task.json中有如下任务：

        {
            "label": "build:debug_robot_tracker",
            "type": "shell",
            "command": ". script/build_debug_robot_tracker.sh",
            "options": {
                "cwd": "${workspaceFolder}" // 设置工作目录为当前工作区
            },
            "presentation": {
                "reveal": "always",
                "panel": "shared",
                "clear": false
            },
            "group": "build"
        },

luanch.json中有如下启动任务：

        {
            "name" : "ROS2_Debug: robot_tracker",
            "type" : "ros",
            "request" : "debug_launch",
            "target" : "${workspaceFolder}/install/robot_tracker/share/robot_tracker/launch/debug_robot_tracker.launch.py",
            "preLaunchTask": "build:debug_robot_tracker",
        },

尝试过的解决方法：

[描述您已经尝试过的任何解决方法或方法。这可以帮助其他人了解您遇到问题的具体情况，并避免给出与您已经尝试过的解决方案相同的答案。]

# ***************************************************
# *******Copyright (C),2019-2099,Coder*******
# *	文件名  	：	debug_robot_tracker.launch.py
# *	文件功能    ：	Robot Sensor包Debug版本的launch文件
# *	编程者      ：	Coder
# *	日期        ：	2024.11.05
# *	编号-----作者---------日期-------注释
# *	00      Coder    2024.11.05	创建
# *	说明：Robot Sensor包Debug版本的launch文件
# ***************************************************
import os
from launch import LaunchDescription
from launch_ros.actions import Node
from launch.events import Shutdown
from launch.event_handlers import OnProcessExit
from launch.substitutions import LaunchConfiguration
from ament_index_python.packages import get_package_share_directory
from launch.actions import DeclareLaunchArgument, EmitEvent, RegisterEventHandler

def generate_launch_description():
    
    robot_tracker_share_directory = get_package_share_directory('robot_tracker')
    robot_sensor_share_directory = get_package_share_directory('robot_sensor')
    
    rviz_config_file = LaunchConfiguration('rviz_config') # RViz配置文件相对路径
    robot_tracker_yaml_config_file = LaunchConfiguration('robot_tracker_yaml_config') # RViz配置文件相对路径
    robot_sensor_yaml_config_file = LaunchConfiguration('robot_sensor_yaml_config') # RViz配置文件相对路径
    
    declare_robot_tracker_yaml_config_file_cmd = DeclareLaunchArgument(
        'robot_tracker_yaml_config',
        default_value = os.path.join(robot_tracker_share_directory, 'config', 'robot_tracker.yaml'),
        description='Full path to the robot_tracker YAML config file to use')
    
    declare_robot_sensor_yaml_config_file_cmd = DeclareLaunchArgument(
        'robot_sensor_yaml_config',
        default_value = os.path.join(robot_sensor_share_directory, 'config', 'robot_sensor.yaml'),
        description='Full path to the robot_sensor YAML config file to use')
    
    declare_rviz_config_file_cmd = DeclareLaunchArgument(
        'rviz_config',
        default_value = os.path.join(robot_tracker_yaml_config_file, 'rviz', 'robot_tracker.rviz'),
        description='Full path to the RVIZ config file to use')
    
    start_robot_sensor_cmd = Node(
        package='robot_sensor',                         # Robot Sensor软件包
        executable='robot_sensor_node',                      # 可执行文件为robot_tracker_node
        name='robot_sensor_node',                          # 节点名称为robot_tracker  
        parameters=[robot_sensor_yaml_config_file])         
    
    start_robot_tracker_cmd = Node(
        package='robot_tracker',                         # Robot Sensor软件包
        executable='robot_tracker_node',                      # 可执行文件为robot_tracker_node
        name='robot_tracker_node',                          # 节点名称为robot_tracker  
        parameters=[robot_tracker_yaml_config_file])   

    # 启动RViz
    start_rviz_cmd = Node(
        package='rviz2',                         # RViz2软件包
        executable='rviz2',                      # 可执行文件为rviz2
        arguments=['-d', rviz_config_file],
        output='screen',)                        # 输出到屏幕
    
    
    # 退出事件处理器
    exit_event_handler = RegisterEventHandler(
        event_handler=OnProcessExit(
            target_action=start_rviz_cmd,       # 关联的目标动作是启动RViz
            on_exit=EmitEvent(event=Shutdown(reason='rviz exited'))))  # 退出时触发关闭事件
    
    # 创建启动描述并填充
    ld = LaunchDescription()
    ld.add_action(declare_robot_tracker_yaml_config_file_cmd)  # 添加YAML配置文件参数
    ld.add_action(declare_robot_sensor_yaml_config_file_cmd)  # 添加YAML配置文件参数
    ld.add_action(declare_rviz_config_file_cmd)  # 添加RViz配置文件参数
    ld.add_action(start_robot_sensor_cmd)  # 启动Robot Sensor
    ld.add_action(start_robot_tracker_cmd)  # 启动Robot Sensor
    ld.add_action(start_rviz_cmd)         # 启动RViz
    ld.add_action(exit_event_handler)      # 添加退出事件处理器
    return ld  # 返回构建好的启动描述

if __name__ == '__main__':
    generate_launch_description()

环境如下
Executing dumper with the following environment:
{
"SHELL": "/bin/zsh",
"ROS_VERSION": "2",
"LSCOLORS": "Gxfxcxdxbxegedabagacad",
"LESS": "-R",
"APPLICATION_INSIGHTS_NO_DIAGNOSTIC_CHANNEL": "1",
"ROS_PYTHON_VERSION": "3",
"ELECTRON_RUN_AS_NODE": "1",
"PWD": "/home/lixinlong/robot_ws",
"LOGNAME": "lixinlong",
"XDG_SESSION_TYPE": "tty",
"VSCODE_ESM_ENTRYPOINT": "vs/workbench/api/node/extensionHostProcess",
"MOTD_SHOWN": "pam",
"HOME": "/home/lixinlong",
"AUTOJUMP_ERROR_PATH": "/home/lixinlong/.local/share/autojump/errors.log",
"LANG": "C",
"LS_COLORS": "",
"SSL_CERT_DIR": "/usr/lib/ssl/certs",
"AMENT_PREFIX_PATH": "/home/lixinlong/robot_ws/install/robot_sensor:/home/lixinlong/robot_ws/install/robot_interfaces:/opt/ros/humble",
"CMAKE_PREFIX_PATH": "/home/lixinlong/robot_ws/install/robot_sensor:/home/lixinlong/robot_ws/install/robot_interfaces",
"VSCODE_AGENT_FOLDER": "/home/lixinlong/.vscode-server",
"VSCODE_L10N_BUNDLE_LOCATION": "vscode-local:/c%3A/Users/11233/.vscode/extensions/ms-ceintl.vscode-language-pack-zh-hans-1.95.2024103009/translations/extensions/vscode.json-language-features.i18n.json",
"AUTOENV_HOME": "/home/lixinlong/.autoenv",
"COLCON_PREFIX_PATH": "/home/lixinlong/robot_ws/install",
"SSH_CONNECTION": "192.168.196.1 11987 192.168.196.128 22",
"XDG_SESSION_CLASS": "user",
"VSCODE_HANDLES_SIGPIPE": "true",
"PYTHONPATH": "/home/lixinlong/robot_ws/install/robot_interfaces/local/lib/python3.10/dist-packages:/opt/ros/humble/lib/python3.10/site-packages:/opt/ros/humble/local/lib/python3.10/dist-packages",
"ZSH": "/home/lixinlong/.oh-my-zsh",
"USER": "lixinlong",
"AUTOJUMP_SOURCED": "1",
"DISPLAY": "192.168.10.4:0.0",
"SHLVL": "0",
"PAGER": "less",
"VSCODE_CWD": "/home/lixinlong",
"XDG_SESSION_ID": "3",
"LD_LIBRARY_PATH": "/home/lixinlong/robot_ws/install/robot_interfaces/lib:/opt/ros/humble/opt/rviz_ogre_vendor/lib:/opt/ros/humble/lib/x86_64-linux-gnu:/opt/ros/humble/lib",
"XDG_RUNTIME_DIR": "/run/user/1000",
"SSL_CERT_FILE": "/usr/lib/ssl/certs/ca-certificates.crt",
"ROS_LOCALHOST_ONLY": "0",
"SSH_CLIENT": "192.168.196.1 11987 22",
"VSCODE_CLI_REQUIRE_TOKEN": "7fcae6c1-9ef5-477b-8ca8-391800a5fede",
"LC_ALL": "en_US.UTF-8",
"XDG_DATA_DIRS": "/usr/share/gnome:/usr/local/share:/usr/share:/var/lib/snapd/desktop",
"BROWSER": "/home/lixinlong/.vscode-server/cli/servers/Stable-e8653663e8840adaf45af01eab5c627a5af81807/server/bin/helpers/browser.sh",
"PATH": "/home/lixinlong/.local/bin:/home/lixinlong/.local/bin:/home/lixinlong/.vscode-server/cli/servers/Stable-e8653663e8840adaf45af01eab5c627a5af81807/server/bin/remote-cli:/opt/ros/humble/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin",
"DBUS_SESSION_BUS_ADDRESS": "unix:path=/run/user/1000/bus",
"VSCODE_NLS_CONFIG": "{"userLocale":"zh-cn","osLocale":"zh-cn","resolvedLanguage":"zh-cn","defaultMessagesFile":"/home/lixinlong/.vscode-server/cli/servers/Stable-e8653663e8840adaf45af01eab5c627a5af81807/server/out/nls.messages.json","languagePack":{"translationsConfigFile":"/home/lixinlong/.vscode-server/data/clp/992791cd017d0441f609c48108aa8c37.zh-cn/tcf.json","messagesFile":"/home/lixinlong/.vscode-server/data/clp/992791cd017d0441f609c48108aa8c37.zh-cn/e8653663e8840adaf45af01eab5c627a5af81807/nls.messages.json","corruptMarkerFile":"/home/lixinlong/.vscode-server/data/clp/992791cd017d0441f609c48108aa8c37.zh-cn/corrupted.info"},"locale":"zh-cn","availableLanguages":{"*":"zh-cn"},"_languagePackId":"992791cd017d0441f609c48108aa8c37.zh-cn","_languagePackSupport":true,"_translationsConfigFile":"/home/lixinlong/.vscode-server/data/clp/992791cd017d0441f609c48108aa8c37.zh-cn/tcf.json","_cacheRoot":"/home/lixinlong/.vscode-server/data/clp/992791cd017d0441f609c48108aa8c37.zh-cn","_resolvedLanguagePackCoreLocation":"/home/lixinlong/.vscode-server/data/clp/992791cd017d0441f609c48108aa8c37.zh-cn/e8653663e8840adaf45af01eab5c627a5af81807","corruptedFile":"/home/lixinlong/.vscode-server/data/clp/992791cd017d0441f609c48108aa8c37.zh-cn/corrupted.info"}",
"ROS_DISTRO": "humble",
"VSCODE_HANDLES_UNCAUGHT_ERRORS": "true",
"OLDPWD": "/home/lixinlong",
"VSCODE_IPC_HOOK_CLI": "/run/user/1000/vscode-ipc-891140e9-a245-4594-a6b3-063bb34445e3.sock",
"": "/usr/bin/env"
}

错误时日志：
cd /home/lixinlong/robot_ws ; /usr/bin/env /usr/bin/python3.10 /home/lixinlong/.vscode-server/extensions/ms-python.debugpy-2024.12.0-linux-x64/bundled/libs/debugpy/adapter/../../debugpy/launcher 41575 -- /home/lixinlong/.vscode-server/extensions/ms-iot.vscode-ros-0.9.2/assets/scripts/ros2_launch_dumper.py /home/lixinlong/robot_ws/install/robot_tracker/share/robot_tracker/launch/debug_robot_tracker.launch.py
Caught multiple exceptions when trying to load file of format [py]:

PackageNotFoundError: "package 'robot_tracker' not found, searching: ['/home/lixinlong/robot_ws/install/robot_sensor', '/home/lixinlong/robot_ws/install/robot_interfaces', '/opt/ros/humble']"
InvalidFrontendLaunchFileError: The launch file may have a syntax error, or its format is unknown

机器人小伊

根据您提供的错误信息和代码，这里有几个可能导致启动文件 debug_robot_tracker.launch.py 报错的问题。我将逐一分析并提供可能的解决方案：

包未找到错误（PackageNotFoundError）:
错误信息 PackageNotFoundError: "package 'robot_tracker' not found, searching: ['/home/lixinlong/robot_ws/install/robot_sensor', '/home/lixinlong/robot_ws/install/robot_interfaces', '/opt/ros/humble'] 表明系统无法在指定的路径中找到 robot_tracker 包。

解决方案:
- 确保 robot_tracker 包已经正确构建并安装在 ROS 2 工作空间中。检查 robot_ws/src/ 目录下是否存在 robot_tracker 包的源代码。
- 确认你的工作空间已经被正确设置并源代码已经编译。你可以使用 colcon build 命令来构建工作空间。
- 确保 source install/setup.bash 已经被执行，以便设置环境变量，让 ROS 2 能够找到新安装的包。
RViz配置文件路径错误:
在代码中，declare_rviz_config_file_cmd 的 default_value 使用了 robot_tracker_yaml_config_file 变量，这是不正确的，因为 robot_tracker_yaml_config_file 是一个指向 YAML 配置文件的路径，而不是一个目录。

解决方案:
- 修改 declare_rviz_config_file_cmd 的 default_value 以正确指向 RViz 配置文件的路径。例如：
```
declare_rviz_config_file_cmd = DeclareLaunchArgument(
    'rviz_config',
    default_value=os.path.join(robot_tracker_share_directory, 'rviz', 'robot_tracker.rviz'),
    description='Full path to the RVIZ config file to use')
```
代码格式和语法:
你的代码在 Python 脚本的末尾有一个语法错误。if name == 'main': 应该是 if __name__ == '__main__':。

解决方案:
- 修改代码末尾的 if 语句为 if __name__ == '__main__':。
使用正确的 Python 解释器和环境:
确保你在使用正确的 Python 解释器和 ROS 2 环境。有时候，特别是在使用 VSCode 或其他 IDE 时，可能需要手动配置 Python 解释器路径。

应用以上解决方案后，重新尝试运行你的启动文件。如果问题仍然存在，可能需要检查 ROS 2 的日志输出以获取更多信息。

以上为生成回答，仅供参考～

小鱼

@1123347532 差个source

bstd321

@小鱼在 launch启动报错中说：

@1123347532 差个source

脚本里面写. install/setup.zsh了但是还是找不到，即便是在终端里把脚本按顺序敲一遍也没有，但是install目录下能看到robot_tracker这个编译的包

小鱼

@1123347532 把环境变量都检查一遍

bstd321

问题已解决，原因是环境变量AMENT_PREFIX_PATH错误，虽然没有找到这个变量为什么出错导致查找不到robot_tracker包，但我通过在lauch.json配置中手动修复该环境变量后启动正常，修改前配置为

// robot_tracker_launch_task
        {
            "name" : "ROS2_Debug: robot_tracker",
            "type" : "ros",
            "request" : "launch",
            "target" : "${workspaceFolder}/install/robot_tracker/share/robot_tracker/launch/debug_robot_tracker.launch.py",
            "preLaunchTask": "build:debug_robot_tracker",
            "launch": ["rviz"]
        },

修改后配置为

// robot_tracker_launch_task
{
    "name" : "ROS2_Debug: robot_tracker",
    "type" : "ros",
    "request" : "launch",
    "target" : "${workspaceFolder}/install/robot_tracker/share/robot_tracker/launch/debug_robot_tracker.launch.py",
    "preLaunchTask": "build:debug_robot_tracker",
    "launch": ["rviz"],
    "env":{
        "AMENT_PREFIX_PATH" : "/opt/ros/humble:${workspaceFolder}/install/robot_tracker"
    }
},

@小鱼感谢大佬