VS Code intellisense not finding kconfig options

[Nick_RA]

Something seems to have broken in my VSC and/or Nordic extensions. Intellisense seems to be working for code, but cannot resolve any of my custom kconfig options.

I use some boolean kconfig CONFIG_WHATEVER along with some #if defined(CONFIG_WHATEVER) to enable/disable code blocks. But everything is greyed out now and intellisense for the code within that block is also disabled. I can right-click the CONFIG_WHATEVER and "view definition" (=1 if enabled), and all code compiles exactly as it should.

Other "standard" options like CONFIG_SERIAL behave fine in the same project.

Can you give any hints where to look or how to fix please?

(AI suggested solution of adding "C_Cpp.default.configurationProvider": "nordic-semiconductor.nrf-connect" to settings.json didn't work)

NCS 3.02

VS Code version:

Version: 1.114.0 (user setup)
Commit: e7fb5e96c0730b9deb70b33781f98e2f35975036
Date: 2026-04-01T09:27:11Z
Electron: 39.8.3
ElectronBuildId: 13658728
Chromium: 142.0.7444.265
Node.js: 22.22.1
V8: 14.2.231.22-electron.0
OS: Windows_NT x64 10.0.26200

[Kenneth]

Hello,

Any way we can recreate it here?

Normally I would suggest that you do a pristine build and that you have the specific build active in the APPLICATIONS window in nRF Connect extension in VS code.

Kenneth

[Nick_RA]

Probably not. The really weird thing is I recently made a copy of the entire project folder in order to do some hacking about to troubleshoot a subtle power consumption problem I had, and this copy works OK!

I have tried cleaning the build configuration and doing a pristine build but that makes no difference. 

On the "good" copy I can hover over for example CONFIG_MY_CUSTOM_FOO and it looks up the value. On the "bad" copy it doesn't. Yet if I right-click and select "go to definition" on the bad copy it jumps to  \include\generated\zephyr\autoconf.h and shows "1" if configured.

The contents of the ./vscode folder c_cpp_properties.json and settings.json match between the two.

I can only guess there is a cached file somewhere making it go wrong?

[Kenneth]

Nick_RA said:

I can only guess there is a cached file somewhere making it go wrong?

Looks like it yes, does manually delete the build folder work?

Kenneth

[Nick_RA]

No, it's also the same for other build configurations.

[Turbo J]

Same problem here when using sysbuild.

Fix is relatively simple: Select the application build folder (example: MyProject/build/MyProject) in "Applications" tab. This allows the extension to read correct .config variables.

The bad thing here is that it breaks Segger Ozone debug support, which wants the "build" folder to be active in order to work correctly. Could be a problem with my very custom cmake scripts, though.

Note that I am still on the oldstable nrf connect extension version (2026.1.1327) so YMMV.