Add support for pixi build

[hadim]

This is a simple POC adding support for pixi build. The motivation is to be able to simply and quickly test a custom rattler-build binary within a conda-forge feedstock.

With this PR you can now tweak the pixi.toml of any feedstock that way:

@@ -3,20 +3,22 @@
 # -*- mode: toml -*-
 
 #                             VVVVVV  minimum `pixi` version
-"$schema" = "https://pixi.sh/v0.36.0/schema/manifest/schema.json"
+# "$schema" = "https://pixi.sh/v0.36.0/schema/manifest/schema.json"
 
-[project]
+[workspace]
 name = "katago-feedstock"
 version = "3.50.0"  # conda-smithy version used to generate this file
 description = "Pixi configuration for conda-forge/katago-feedstock"
 authors = ["@conda-forge/katago"]
 channels = ["conda-forge"]
-platforms = ["linux-64", "osx-64", "win-64"]
+platforms = ["linux-64", "osx-64", "win-64", "osx-arm64"]
+preview = ["pixi-build"]
 
 [dependencies]
 conda-build = ">=24.1"
 conda-forge-ci-setup = "4.*"
-rattler-build = "*"
+# rattler-build = "*"
+rattler-build = { git = "https://github.com/hadim/rattler-build.git", branch = "pixi_build" }
 
 [tasks]
 [tasks.inspect-all]

Simply set the location of rattler-build repo or URL you want to test with rattler-build = { git = "https://github.com/hadim/rattler-build.git", branch = "pixi_build" } and then the c-f feedstock will build it and use it during the c-f builds on the c-f CIs.

---

This POC is leveraging the pixi-build-rattler-build backend but moving forward it might make sense to use pixi-build-rust instead.

[wolfv]

Cool! I also wanted to try this out :)

[hadim]

I am done here as it is a simple POC. Please let me know if you would like to review and merge, or I can also close if you prefer to take care of it later.

[wolfv]

Awesome! Sorry for letting it linger :)

[lucascolley]

it seems like things still work for me switching to pixi-build-rust instead — should we do that? Maybe there are edge-cases here that wouldn't be covered?

[wolfv]

Would be great to move to the Rust backend, indeed.