Default Rust configuration not working

[fairking]

Hi guys. I would like to start using the debugger for my rust code. But apparently it is not working as intended.
I am on Linux Fedora and VSCodium.
I downloaded the extension v.1.7.0.

1. I create a folder for my project mkdir exam1,
2. I go to that folder cd exam1,
3. I create a rust file touch main.rs,
4. I open the VSCodium with the folder exam1,
5. If I press F5 it asks to create a launch.json,
6. I press F5 again and it says Unable to find executable for <your program>,
7. I change <your program> to main.rs,
8. If I press F5 again it says main.rs does not contain any 'host' platform architecture,
9. I looked at the documentation but it only contains a bunch of commands and options I don't understand.

P.S. I am able to compile rustc main.rs and run the app ./main.

The question is: can someone please explain me in a simple way what I am missing to run the debugger?
The Manual fails to provide some kind of GetStarted point so it is not useful to me.

[fairking]

BTW, I tried to understand the documentation, but it's written in such way that only developer of vscode-lldb can understand it.

[vadimcn]

"program" should point to the executable binary file that your compiler produces. In your case it's "main", or preferably, "${workspaceFolder}/main", to remove ambiguity about where it is located. The other thing you'll need to do is ask the compiler to emit the debugging information into the binary by passing it the "-g" flag.

it's written in such way that only developer of vscode-lldb can understand it

Sorry, but I have to presuppose some basic level of knowledge about how compilation and debugging work. There are links to more background information are the end of the extension readme.
What terms did you find confusing and what terms you would have liked to see instead?

[fairking]

Can I just click run debugger without all of that fuss. Is there any example of launch.json at least?

[vadimcn]

Use "Run/Add Configuration..." menu, there will be several CodeLLDB configuration templates in the popup to choose from.

[Alchnator]

it seem like i have the same issue.
if i try the run/debug buttons that vscode's codelens show above functions. it runs fine.

but "run" and "run and without debugging" from the run menu seems to just look for a executable described on the program field of launch.json without ever trying to compile/built it.

if i make the program on launch.json point to the same executable location that is created by the the codelens run/debug options, it will launch the executable that is there. but else it will just say it can't find the executable.

[vadimcn]

seems to just look for a executable described on the program field of launch.json without ever trying to compile/built it.

That is exactly what it is supposed to do. CodeLLDB can be used with many compiled languages, so it is not feasible to build in the knowledge about how to invoke each compiler (of which there can be multiple for the same language, see e.g. C++).
Instead, you are expected to invoke your compiler/build system, then provide path of the produced executable binary to debugger. To automate this step in VSCode, you can use preLaunchTask.

if i try the run/debug buttons that vscode's codelens show above functions. it runs fine.

The language extension that provides the code lens, is targeted at a particular language, it is much easier for them to know how to compile programs in that language. Especially since Rust has a standard build system.

---

...well, okay: as an exception to the above rule of thumb, CodeLLDB actually can invoke Cargo for you. But this sort of thing is uncommon among native debugging tools.

[Alchnator]

yeah that's definitely clears things up, i was kinda wondering that. i guess i got bad luck with the guides i found.
being stuck inside VS for the last 20 years does that for you i guess.

thanks for the explanation