Build issue with NCS v1.9.1 using Toolchain v2.0.0

[Praveen Deshmane]

Hi DevZone Community,

I am facing a build issue while working with the following environment:

Environment

• SDK: nRF Connect SDK v1.9.1

• Hardware: nRF9160 DK (custom board)

• Toolchain: v2.0.0
  
  

Since older toolchain versions (v1.x.x) are no longer supported, Toolchain v2.0.0 or later is required for building and execution. However, I am currently unable to build my project using Toolchain v2.0.0 with NCS v1.9.1.

I am encountering the following error during the build process:

west build --build-dir d:/im830/build d:/im830 --pristine --board im830_nrf9160_ns -- -DNCS_TOOLCHAIN_VERSION="NONE" -DCONFIG_DEBUG_OPTIMIZATIONS=y -DCONFIG_DEBUG_THREAD_INFO=y -DCONF_FILE="prj.conf" -DBOARD_ROOT=d:/im830

-- west build: generating a build system
Including boilerplate (Zephyr base): C:/ncs/v1.9.1/zephyr/cmake/app/boilerplate.cmake
-- Application: D:/im830
-- Zephyr version: 2.7.99 (C:/ncs/v1.9.1/zephyr), build: v2.7.99-ncs1-1
-- Found Python3: C:/ncs/toolchains/v2.0.0/opt/bin/python.exe (found suitable exact version "3.8.2") found components: Interpreter
-- Found west (found suitable version "0.13.1", minimum required is "0.7.1")
-- Board: im830_nrf9160_ns, Revision: 0.1.0
-- Cache files will be written to: C:/ncs/v1.9.1/zephyr/.cache
-- Found host-tools: zephyr 0.14.1 (C:/ncs/toolchains/v2.0.0/opt/zephyr-sdk)
-- Found dtc: C:/ncs/toolchains/v2.0.0/opt/bin/dtc.exe (found suitable version "1.4.7", minimum required is "1.4.6")
-- Found toolchain: zephyr 0.14.1 (C:/ncs/toolchains/v2.0.0/opt/zephyr-sdk)
-- Found BOARD.dts: D:/im830/boards/arm/im830_nrf9160/im830_nrf9160_ns.dts
-- Generated zephyr.dts: D:/im830/build/zephyr/zephyr.dts
-- Generated devicetree_unfixed.h: D:/im830/build/zephyr/include/generated/devicetree_unfixed.h
-- Generated device_extern.h: D:/im830/build/zephyr/include/generated/device_extern.h
-- Including generated dts.cmake file: D:/im830/build/zephyr/dts.cmake

warning: Experimental symbol NET_SOCKETS_OFFLOAD is enabled.


D:/im830/prj.conf:59: warning: attempt to assign the value 'y' to the undefined symbol AT_CMD

D:/im830/prj.conf:60: warning: attempt to assign the value 'y' to the undefined symbol AT_NOTIF

D:/im830/prj.conf:116: warning: attempt to assign the value 'y' to the undefined symbol BSD_LIBRARY

D:/im830/prj.conf:117: warning: attempt to assign the value 'n' to the undefined symbol BSD_LIBRARY_SYS_INIT
Parsing D:/im830/Kconfig
Loaded configuration 'D:/im830/boards/arm/im830_nrf9160/im830_nrf9160_ns_defconfig'
Merged configuration 'D:/im830/prj.conf'
Merged configuration 'D:/im830/build/zephyr/misc/generated/extra_kconfig_options.conf'

error: Aborting due to Kconfig warnings

CMake Error at C:/ncs/v1.9.1/zephyr/cmake/kconfig.cmake:272 (message):
  command failed with return code: 1
Call Stack (most recent call first):
  C:/ncs/v1.9.1/zephyr/cmake/app/boilerplate.cmake:544 (include)
  C:/ncs/v1.9.1/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:24 (include)
  C:/ncs/v1.9.1/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:35 (include_boilerplate)
  CMakeLists.txt:5 (find_package)


-- Configuring incomplete, errors occurred!
FATAL ERROR: command exited with status 1: 'C:\ncs\toolchains\v2.0.0\opt\bin\cmake.EXE' '-DWEST_PYTHON=C:\ncs\toolchains\v2.0.0\opt\bin\python.exe' '-Bd:\im830\build' '-Sd:\im830' -GNinja -DBOARD=im83
0_nrf9160_ns -DNCS_TOOLCHAIN_VERSION=NONE -DCONFIG_DEBUG_OPTIMIZATIONS=y -DCONFIG_DEBUG_THREAD_INFO=y -DCONF_FILE=prj.conf -DBOARD_ROOT=d:/im830

 *  The terminal process terminated with exit code: 1. 
 *  Terminal will be reused by tasks, press any key to close it.

I would like to know:

1. Is it officially supported to build an application using NCS v1.9.1 with Toolchain v2.0.0?

2. If not, is there any recommended workaround or migration approach?

Your guidance and suggestions would be greatly appreciated.

Thank you.

[Priyanka]

Hi Praveen,

We generally recommend using the same SDK and Toolchain versions. So please try using SDK v2.0.0

Please take a look at the following migration guide to transition from SDK 1.x.x to 2.x.x

https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/releases_and_maturity/migration/migration_guide_1.x_to_2.x.html 

-Priyanka

[Praveen Deshmane]

Hello Priyanka,

Thank you for your response.

Migrating from NCS v1.9.1 to v2.0.0 would require significant changes to the application source code.

Is there any way to continue using the v1.9.1 toolchain?

- Praveen

[Priyanka]

Hi Praveen,

I will check this internally. In the meantime, could you tell me whether you face any significant issues when working with SDK v1.9.1 + toolchain v1.9.1?

-Priyanka

[Praveen Deshmane]

Hello Priyanka,

Recently, the nRF Connect for VS Code extension was automatically updated to version 2026.1.1327. Since this update, we are no longer able to see or select the v1.9.1 toolchain. The extension displays “Install Toolchain to get started”, and when selecting Install Toolchain, only toolchain versions from v3.2.1 down to v2.0.0 are available. There is no option to install or select v1.9.1.

Due to this limitation, I installed the v2.0.0 toolchain and attempted to build and flash our application using it. However, the build and flashing process was unsuccessful.

As per your previous guidance recommending the use of matching SDK and toolchain versions, this means our application cannot be built unless we migrate from SDK v1.9.1 to v2.0.0. At present, we do not have plans to migrate to v2.0.0, as this would require significant changes to the application source code and considerable development time.

Currently, we are facing an issue on our production terminals (devices), and in order to investigate the root cause, we need to analyze the terminal logs using our development environment. However, since we are unable to build the development environment with SDK v1.9.1 (vs code extension issue), this investigation is blocked.

Given the impact on production issue analysis, we kindly request your urgent support on this matter and guidance on how to proceed as soon as possible.

Is there any way to continue using the v1.9.1 toolchain?

Thank you for your support.

- Praveen Deshmane

[Priyanka]

Hi Praveen,

I am able to replicate the issue on my end as well and I am checking this internally. I will update you regarding this.

-Priyanka

[Praveen Deshmane]

Hello Priyanka,

I have identified a temporary workaround.

By downgrading all nRF-related VS Code extensions, I am now able to see and use the v1.9.1 SDK and toolchain again. The versions currently working are:

• 2023.9.4 – nRF Connect for VS Code Extension Pack

• 2023.9.336 – nRF Connect for VS Code

• 2023.9.57 – nRF DeviceTree

• 2023.9.94 – nRF Kconfig

• 2023.9.29 – nRF Terminal

However, based on this behavior, it appears that in the latest VS Code extension releases, support for displaying and using the v1.9.1 toolchain has been removed or deprecated.

Could you please confirm whether this is the expected behavior and if there is an official recommendation for users who still need to work with SDK v1.9.1 and toolchain?

Thank you.

 - Praveen Deshmane