> For the complete documentation index, see [llms.txt](https://campus-rover.gitbook.io/lab-notebook/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://campus-rover.gitbook.io/lab-notebook/yyy/advanced-fixing-build-problems.md).

# Advanced: Help me troubleshoot weird build problems

## Notes

You really need to know what you are doing when you are dealing at this level.

## Radical Cleanup

* It turns out that it is safe to delete the build and devel subdirectories in ROS.
* Sometimes this helps:

```
cd ~/catkin_ws
rm -rf build/ devel/
catkin_make
source devel/setup.bash
```

## Another way

* First: lean your build by running "catkin\_make clean" in the root of your workspace.
* Second: remake your project with "catkin\_make"
* Third: re-source the devel/setup.bash in your workspace.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://campus-rover.gitbook.io/lab-notebook/yyy/advanced-fixing-build-problems.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.