Can not install toolchain for 3rd party SDK (ie stock zephyr)

[kent96822]

Development environment: MacOS Sequoia (15.4.1), Visual Studio Code v1.108 0,  nrfConnect 2026.1.1242

I am trying to develop a "workspace" project with a nRF52840DK as my development target using the nrf-connect vs-code extension. I am unable to figure out how to install/select the stock zephyr toolchain. While I know the nordic toolchain will often work, I am experiencing a problem where the nordic toolchain gives posix errors that the stock toolchain does not. Thus I am revisiting how to install / select a third party tool chain. (It also is a bad practice to develop with the nordic toolchain, but then have build server use the stock toolchain. I don't need those gremlins.)

My development environment has stock zephyr base directory of "/opt/zephyr". There I have a "venv" to source for "west" development. I also have a "/opt/nordic/ncs" tree for nordic SDKs.

FWIW, I have the current zephyr toolchain installed at "/opt/zephyr/zephyr-sdk-0.17.4" as installed by "west sdk install". 

To recreate the problem I performed the following steps:

1)  using "Manage SDKs", I installed 3rd party SDK from the stock zephyr GitHub directory: "zephyrproject-rtos/zephyr" and chose v4.3.0. Destination "/opt/zephyr/sdk". Directory "v4.3.0" appeared in the destination directory with all the appropriate info cloned.

2) using "Create new application", I selected "copy from sample", I choose "Hello World" using the v4.3.0 SDK (just installed).

3) Then using "Manage SDKs", I selected "Manage west workspace" -> "Create west workspace" for the newly created application.

4) I then ran "Manage SDKs" -> "Manage west workspace" -> "Run west update". 

5) After that I could run "add build configuration" & build, but I was not able to select the stock zephyr toolchain.  The application built with the nordic toolchain selected. (Application frame shows Zephyr v4.3.0 as SDK. Action frame shows "nRF Connect SDK Toolchain v2.8.0)

6) Using a terminal, I was able to cd into the application root (ie the west directory) and after sourcing the zephyr venv environment (for me "source /opt/zephyr/venv/bin/activate", I was able to run "west sdk list" and see 0.17.4 listed as installed. I then change to application directory and run

```

(venv) $ west configure build.board nrf52840dk/nrf52840

(venv) $ west build -p

```

And I observe the application built with the stock toolchain, not the nordic one. I also observe the NRF CONNECT frames show "build configuration stale. Run pristine build".  Selecting "Pristine Build" results in a "Unable to build: SDK not found." error.

Help in installing a third party toolchain would be appreciated. (Or really just selecting it: "west sdk install" works fine to get it, I just can't select it.)

[Vidar Berg]

Hello,

First time I'm trying to use the Zephyr SDK instead of the NCS toolchain on macOS, but it seems to work fine as long as I open VS code from the terminal to let it inherit the build environment. Could you try the same on your end to see if it works for you as well?

Opening VS code from terminal by running "code ." from the workspace directory

(https://code.visualstudio.com/docs/setup/mac#_launch-vs-code-from-the-command-line):

 

Best regards,

Vidar

[kent96822]

Hi Vidar.

Sorry I took so long to get back you. I Didn't realize you were nordic support & just thought it was another user suggesting a work-around.

As you correctly point out, starting vs-code from a terminal the west environment activated allows for selection of the stock toolchains in build. Once the builds complete, the `actions` pane shows the selected toolchain. (And more importantly, the proper toolchain is used -- turns out the three projects I am working on now -- 1 with nordic sdk, one with zephyr-stock 4.3.0 & one with zephyr-stock 3.7.1LTS all require their corresponding toolchains to properly complile code.)

The reason I didn't recognize your solution is that I was looking for something like "in settings set this json value" or some other method directly from the vs-code GUI. If you can confirm that the stock toolchains must be installed outside of the GUI and can not be selected except via the method you have identified, I'll be glad to mark this as the accepted answer.

Thanks again for your help & sorry I was so slow on the uptake.

Kent

[Vidar Berg]

Hi Kent,

No problem. Looking back I can see that my answer may have sounded more like a workaround than a proper solution. What’s happening is that before looking for installed Zephyr SDKs in the CMake package registry, the extension checks if build tools such as west are available on PATH. Only if they are found will the installed/registered Zephyr SDK(s) be displayed. (NCS toolchains don’t require this check since they bundle the build tools.) Another solution is update your PATH in ~/.zshrc to include the path to where you your 'west' executable is located. Then you won’t need to launch VS Code from the terminal to inherit a working build environment.

kent96822 said:

If you can confirm that the stock toolchains must be installed outside of the GUI and can not be selected except via the method you have identified

Correct, the GUI only supports installation of NCS toolchains. 

Best regards,

Vidar