# Debug Autoware

This page provides some methods for debugging Autoware.

## Print debug messages

The essential thing for debug is to print the program information clearly, which can quickly judge the program operation and locate the problem. Autoware uses ROS 2 logging tool to print debug messages, how to design console logging refer to tutorial [Console logging](<../../../contributing/coding-guidelines/ros-nodes/console-logging/index.md>).

## Using ROS tools debug Autoware

### Using command line tools

ROS 2 includes a suite of command-line tools for introspecting a ROS 2 system. The main entry point for the tools is the command `ros2`, which itself has various sub-commands for introspecting and working with nodes, topics, services, and more. How to use the ROS 2 command line tool refer to tutorial [CLI tools](<https://docs.ros.org/en/humble/Tutorials/Beginner-CLI-Tools.html>).

### Using rviz2

Rviz2 is a port of Rviz to ROS 2. It provides a graphical interface for users to view their robot, sensor data, maps, and more. You can run Rviz2 tool easily by:

```console
rviz2
```

When Autoware launch the simulators, the Rviz2 tool is opened by default to visualize the autopilot graphic information.

### Using rqt tools

RQt is a graphical user interface framework that implements various tools and interfaces in the form of plugins. You can run any RQt tools/plugins easily by:

```console
rqt
```

This GUI allows you to choose any available plugins on your system. You can also run plugins in standalone windows. For example, RQt Console:

```console
ros2 run rqt_console rqt_console
```

#### Common RQt tools

1. rqt\_graph: view node interaction

   In complex applications, it may be helpful to get a visual representation of the ROS node interactions.

   ```console
   ros2 run rqt_graph rqt_graph
   ```
2. rqt\_console: view messages

   rqt\_console is a great gui for viewing ROS topics.

   ```console
   ros2 run rqt_console rqt_console
   ```
3. rqt\_plot: view data plots

   rqt\_plot is an easy way to plot ROS data in real time.

   ```console
   ros2 run rqt_plot rqt_plot
   ```

### Using ros2\_graph

[`ros2_graph`](<https://github.com/kiwicampus/ros2_graph>) can be used to generate [mermaid](<https://mermaid.js.org/>) description of ROS 2 graphs to add on your markdown files.

It can also be used as a colorful alternative to `rqt_graph` even though it would require some tool to render the generated mermaid diagram.

It can be installed with:

```bash
pip install ros2-graph
```

Then you can generate a mermaid description of the graph with:

```bash
ros2_graph your_node

# or like with an output file
ros2_graph /turtlesim -o turtle_diagram.md

# or multiple nodes
ros2_graph /turtlesim /teleop_turtle
```

You can then visualize these graphs with:

- [Mermaid Live Editor](<https://mermaid.live/>)
- Visual Studio Code extension [mermaid preview](<https://marketplace.visualstudio.com/items?itemName=vstirbu.vscode-mermaid-preview>)
- JetBrains IDEs [with native support](<https://www.jetbrains.com/guide/go/tips/mermaid-js-support-in-markdown/>)

### Using ros2doctor

When your ROS 2 setup is not running as expected, you can check its settings with the `ros2doctor` tool.

`ros2doctor` checks all aspects of ROS 2, including platform, version, network, environment, running systems and more, and warns you about possible errors and reasons for issues.

It's as simple as just running `ros2 doctor` in your terminal.

It has the ability to list "Subscribers without publishers" for all topics in the system.

And this information can help you find if a necessary node isn't running.

For more details, see the following official documentation for [Using ros2doctor to identify issues](<https://docs.ros.org/en/humble/Tutorials/Beginner-Client-Libraries/Getting-Started-With-Ros2doctor.html>).

## Using a debugger with breakpoints

Many IDEs (for example Visual Studio Code and CLion) support debugging C/C++ executables with GDB on Linux. The following lists some references for using the debugger:

- [https://code.visualstudio.com/docs/cpp/cpp-debug](<https://code.visualstudio.com/docs/cpp/cpp-debug>)
- [https://www.jetbrains.com/help/clion/debugging-code.html\#useful-debugger-shortcuts](<https://www.jetbrains.com/help/clion/debugging-code.html#useful-debugger-shortcuts>)