Zephyr example-application failed to build

[DaGigabyte]

When building the example-application from https://github.com/zephyrproject-rtos/example-application
using west build -b custom_plank in the example-application root directory, I encountered the following error:

my-app/app/prj.conf:7: warning: attempt to assign the value 'y' to the undefined symbol BLINK

error: Aborting due to Kconfig warnings

Is the example-application compilable using that command above?

[Halogenek]

I encountered almost the same problem and found a solution.
In my case west could not find the board provided in the example-application.
The problem is that when you follow the instructions from the main zephyr project documentation and initialize your workspace and then clone the example-application repository to your ~/zephyrproject folder then the build for the example custom_plank wont work.

You have to go out from your ~/zephyrproject folder to (for example) your main home folder and then follow instructions only from the example-application repository (but still having your venv active from ~/zephyrproject).

So if you do

cd ~/
west init -m https://github.com/zephyrproject-rtos/example-application --mr main my-workspace
cd my-workspace
west update
cd example-application
west build -b custom_plank app

It will work. Why? Don't know - I just started. Someone with bigger experience should explain why following the main documentation creates this build issue.

[ldomaigne]

@DaGigabyte and @Halogenek:

When you run west init ~/zephyrproject during the getting started guide, it creates a west workspace for the zephyr project. A west workspace contains a manifest file west.yml that defines all dependencies (= git repo, at which revision) needed to build a zephyr application. When you do west update, it pulls all these dependencies (or their update).

The example application comes with its own west.yml. So you can't just git clone it to zephyrproject. Also you can't run west init in ~/zephyrproject, as it is already a west workspace if you followed the getting started guide. You need to create a new workspace, as @Halogenek described.

The example application is a good starting point to create a Zephyr application, including Zephyr customization (add some drivers, custom boards, west commands...).

[Halogenek]

I think I found an error in the main docs.
When you follow the getting started guide that instructs you to init your workspace and follow to application development, then in the point Creating an Application you are asked to clone the example application repository into your zephyr workspace.
Doing so will result in errors when you try to build the example for the provided custom_plank board as your workspace is already initialized.

When you follow further instructions and create a new workspace it will work. It was a little confusing for me at first as I followed the instructions step by step.