Set rattler cache to /tmp when building linux from osx

[hadim]

Checklist

• [x] Added a news entry
• [ ] Regenerated schema JSON if schema altered (python conda_smithy/schema.py)

[hadim]

Similar to https://github.com/conda-forge/staged-recipes/pull/28119

[hadim]

LGTM

[hadim]

This should go in build_steps.sh.tmpl, I think. There's a rattler-specific env var we are already using in other platforms, which would be preferred instead of the system-wide XDG setting.

I can move the logic to build_steps.sh.tmpl but I don't see any rattler env var I can re-use there. I am also not aware of another env var to set the rattler cache than XDG_CACHE_HOME.

Also, the current logic is specific to building linux from macOS with docker. Should I keep that same logic if moving to build_steps.sh.tmpl?

[jaimergp]

I am also not aware of another env var to set the rattler cache than XDG_CACHE_HOME.

See https://pixi.sh/v0.21.1/features/environment/#caching. I think RATTLER_CACHE_DIR applies here.

Also, the current logic is specific to building linux from macOS with docker.

Ah, ok, in that case build-locally is ok. Sorry!

[hadim]

I just tested locally and it does not work. It seems like RATTLER_CACHE_DIR only works with pixi.

• The variable shows in the pixi source code.
• Not in the rattler repo
• Not in the rattler-build repo

[hadim]

I opened a ticket at https://github.com/prefix-dev/rattler-build/issues/1171

[hadim]

LGTM once a new rattler-build version is out. See https://github.com/prefix-dev/rattler-build/issues/1171#issuecomment-2468139785 for details

[jaimergp]

Thanks! Ping me again once the new rattler-build is out!

[jaimergp]

Looks like 0.31 is out. Is that what we need for the new env var? Reopening just in case.

[hadim]

Let's wait for 0.31 to make it in https://github.com/conda-forge/rattler-build-feedstock

[hadim]

Actually for conda-smithy, you can merge @jaimergp !