Add "optional" keyword for given project in manifest

Sometimes we have support projects for internal testing and internal resources in the manifest file. It can look like this:

projects:
    - name: proj1
      path: extra/project-1
      revision: master
    - name: proj2
      path: internal_test/test
      remote: secret_internal_repo

When customers get code they also get the manifest file. When they attempt a west init or west update, they will get an error since the internal_test repo is not accessible outside company firewalls.

We would like to se an “optional” argument for two reasons: 1: Give the customer a clear indication that this repo is not needed to build or use the application. 2: West can give a softer warning when this repo is not accessible. E.g.: West was unable to access secret_internal_repo. However, this project has been labeled optional.

[mbolivar-nordic]

You could make that command part of your build process. Pseudo build code:

I think this is more about the README for users that might go either way

[mbolivar-nordic]

The expectation is indeed that the extra step would be necessary before using closed_code. (CI and other places that just need one-shot workspace setup can use west update --gf=+group_closed for brevity.)

I personally don’t find the extra step too onerous, and I’m wary of the extra complexity that comes with adding a third state for projects. There were already unexpected consequences just adding a simple binary active/inactive:

https://github.com/zephyrproject-rtos/west/issues/491

I also got the interaction between imports and group filter wrong in v0.9.0 and had to break compatibility in v0.10.0 as mentioned here:

https://docs.zephyrproject.org/latest/guides/west/release-notes.html#v0-10-0

I’m therefore going to lean on the “conservative about features” design constraint for west, and say that I don’t think an explicit “optional” state is a good idea for now. I understand how that one use case could be made more convenient by that, but I don’t think it justifies the extra complexity by itself.