nRF Kconfig GUI not saving changes

[Mark Szente]

Hi,

I have an issue with nRF Kconfig GUI in VS Code.

My prj.conf is empty, and the _defconfig file of my board contains this:

# Enable UART driver
CONFIG_SERIAL=y

When I open the GUI and search for serial, it indicates that it is turned on, which is correct as it's enabled by default. If I untick it, it shows up in the "changed" tab. However, if I click "Save to file" and select my prj.conf, and error message appears, saying "No changes to save." 

---

My VS Code:

Version: 1.99.0
Commit: 4437686ffebaf200fa4a6e6e67f735f3edf24ada
Date: 2025-04-02T21:35:19.530Z
Electron: 34.3.2
ElectronBuildId: 11161073
Chromium: 132.0.6834.210
Node.js: 20.18.3
V8: 13.2.152.41-electron.0
OS: Darwin arm64 23.2.0

Extension:

Installation
Identifier
nordic-semiconductor.nrf-connect-extension-pack
Version
2025.4.4
Last Updated
2025-04-11, 10:32:13

Using the latest SDK. 

[Marte Myrvold]

Hi,

This could be because the nRF Kconfig GUI disables configs by removing them and setting them to "not set" rather than explicitly disabling them by setting =n. Since CONFIG_SERIAL is enabled in the board file and not in prj.conf, the tool thinks there are no changes to make, as there is no CONFIG_SERIAL to remove from prj.conf.
If you select _defconfig instead, the changes will be saved. However, we do not recommend making changes to the board files, so I would not recommend doing this. A better solution is to set CONFIG_SERIAL=n in prj.conf.

I have reported this internally to the VS Code team.

Best regards,
Marte