nRF project downloads a lot on the first launch for each new project

[MihaelIsaev]

Investigate whether it’s possible to configure Zephyr to fetch only the required toolchains, and explore how to properly cache them using a Docker volume.

Right now, it installs toolchains into the home folder, and what gets downloaded depends on the exact version of Zephyr specified in west.yml in the project.

The goal is to avoid duplicate downloads across projects and reduce both disk usage and startup time.

Any ideas or suggestions on how to best approach this are very welcome!

[xtremekforever]

I think there's a way to do it with a custom west init command. I haven't been able to figure it out myself, but check out the CI for Zephyr here:

https://github.com/swiftlang/swift-embedded-examples/blob/main/.github/workflows/build-zephyr.yml

They seem to be able to just checkout the Zephyr pieces that are in west.yml for the CI, making it pretty quick to download and build.