What common errors do you make when debugging ROS apps?

2 Wrong environment variables

Another common error when debugging ROS apps is setting the wrong environment variables. These are the variables that tell ROS where to find your packages, nodes, and other resources. The most important ones are ROS_MASTER_URI , which specifies the address of the ROS master node, and ROS_PACKAGE_PATH , which specifies the directories where your packages are located. If you don't set them correctly, or if you change them without updating your terminals, you may encounter errors such as unable to locate nodes, topics, or packages. To avoid this, you should always source the setup.bash file of your ROS workspace before running any ROS commands. You can also use the printenv tool to check the values of your environment variables.

3 Mismatched message types

A third common error when debugging ROS apps is using mismatched message types. These are the data structures that define the format and content of the messages that your nodes exchange through topics or services. If you don't use the same message type for both the publisher and the subscriber, or for both the service and the client, you may encounter errors such as serialization errors, deserialization errors, or invalid arguments. To avoid this, you should always use the rostopic and rosservice tools to check the message types of your topics and services. You can also use the rosmsg and rossrv tools to inspect the details of a specific message type.

4 Incorrect launch files

A fourth common error when debugging ROS apps is using incorrect launch files. These are the XML files that define how to start and configure multiple nodes and parameters at once. If you don't write them correctly, or if you use the wrong syntax, attributes, or tags, you may encounter errors such as invalid XML, missing arguments, or unknown nodes. To avoid this, you should always follow the ROS launch file format and conventions. You can also use the roslaunch tool to check and run your launch files.

5 Insufficient logging

A fifth common error when debugging ROS apps is using insufficient logging. This is the process of recording and displaying information about the status, events, and errors of your app. If you don't use logging enough, or if you use the wrong level, format, or destination, you may encounter difficulties in finding and fixing the problems of your app. To avoid this, you should always use the rospy or roscpp logging functions to print messages with different levels of severity and verbosity. You can also use the rosconsole tool to configure and filter the logging output.

6 Inadequate testing

A sixth common error when debugging ROS apps is using inadequate testing. This is the process of verifying and validating the functionality, performance, and reliability of your app. If you don't test your app enough, or if you use the wrong methods, tools, or criteria, you may encounter errors that could have been prevented or detected earlier. To avoid this, you should always use the rostest and rosunit tools to write and run unit tests and integration tests for your app. You can also use the rosbag and rqt tools to record and replay data for testing purposes.