Can I use west to configure a CMake style in-repo but out-of-source setup?

[inkychris]

I was hoping I could get west init to download everything into a local git-ignored directory in my project, much like

cmake -S . -B .build

The -l option gets me close but dumps everything in the folder above which won't be viable when I move it to a self hosted Gitlab runner that has persistent build directories. I think the "free application" model is what I want, but I don't seem to have enough control over the output for my liking.

I have a west manifest in my project repo that I was hoping to use just to get the west command extensions and one module import (hal_espressif in this case). Maybe this is complicating things or there's a better way to achieve this? It's not looking like I can do what I want at least without moving the manifest into a separate repo which seems excessive given that it's describing the dependencies of the project source in the (currently) same repo.

Is this just how it is? I'm used to Python virtual environments and CMake, and this project structuring feels like I'm supposed to be developing in what I'm currently seeing as a build directory.

Thanks in advance!

[yashi]

A simple answer is "No. West is designed to have a workspace".

With a scheme like Python virtual env, you can't have the T3 topology, which West is required to support.

You can have a west.yml just like the following to put everything under your project. But, West still needs a workspace one above your project directory. This puts all modules under your project directory.

manifest:

  projects:
    - name: zephyr
      url: https://github.com/zephyrproject-rtos/zephyr
      revision: main
      path: zephyr
      west-commands: scripts/west-commands.yml
      import:
        path-prefix: foo/modules/
        name-allowlist:
          - cmsis
          - hal_stm32
          - picolibc

  self:
    path: foo

You can run west build in your project directory (not confused with your workspace) without specifying -d BUILD_DIR or source_dir. It puts all artifacts under workspace/foo/build. But West still needs a workspace.

This is what you end up with.

tree -a -L 5 /tmp/ws
/tmp/ws
├── .west
│   └── config
└── foo
    ├── modules
    │   ├── modules
    │   │   ├── hal
    │   │   │   ├── cmsis
    │   │   │   └── stm32
    │   │   └── lib
    │   │       └── picolibc
    │   └── zephyr
    │       ├── CMakeLists.txt
    │       :
    └── west.yml

[inkychris]

Thanks, I found this guide which talks about just accomodating for the parent directory within the repo which I've opted for.

https://blog.golioth.io/improving-zephyr-project-structure-with-manifest-files/