**"Variable is optimized away and not available."**, how can I view those variables in vscode?

[xiongmao86]

Hi, I am trying to debug a project call typst, when I debug the main function, in the local's view, some of the variables are not visible, and showing `Variable is optimized away and not available.

is that because of the way I build? I build with cargo build, and the output is dev [unoptimized + debuginfo]

P.S. Thanks for making this great app, I can't wait to learn more about it.

[lnicola]

Hi. This sometimes happens, e.g. on unused variables. Regardless of that, I don't think you can do much about it. Native language debuggers will always give a worse experience than those for managed languages.

We don't do anything besides setting up the debugging extension. Depending on your platform, you can try another one, there's at least three: C/C++, Native Debug and CodeLLDB.

[xiongmao86]

Hi, @lnicola, thank you for your help. English is not my first language, and I am a little bit confused, the c++ is the c++ extension of microsoft, I have heard of, what is Native Debug refer to?

[lnicola]

• https://marketplace.visualstudio.com/items?itemName=ms-vscode.cpptools
• https://marketplace.visualstudio.com/items?itemName=webfreak.debug
• https://marketplace.visualstudio.com/items?itemName=vadimcn.vscode-lldb

[xiongmao86]

Thank you very much. @lnicola.

[lnicola]

If you try them, can you post your results and operating system, toolchain (-msvc or -gnu if Windows etc.), maybe a small snippet showing the problem for anyone else who has this problem?

[xiongmao86]

I experiment a little bit. The description would be incorrect, sometimes I have to step one more statement for variables of the current statement to show up, plus the description saying it's optimized away, so I assume they are not available. But they are available, only one step away.

[Universal-Invariant]

It seems that variable is optimized away includes variables that have no yet actually been created. Ideally such variables would not be displayed until they are actually valid.

[lnicola]

You're right, but this has been my experience with pretty much all native code debuggers (though the MSVC one is pretty friendly if you enable that Just My Code option), and we can't do anything about it.