Tasks not found when switching from osx-arm64 to osx-64

[ekiefl]

Checks

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pixi, using pixi --version.

Reproducible example

▶▶ pixi init pixi_py --pyproject
✔ Initialized project in /Users/evan/Software/test/pixi_py
▶▶ cd pixi_py/
▶▶ pixi install
✔ Project in /Users/evan/Software/test/pixi_py is ready to use!
▶▶ pixi task add hello "echo hi"
✔ Added task `hello`: echo hi
▶▶ pixi r hello
✨ Pixi task (hello in default): echo hi
hi

Now go into pyproject.toml and replace osx-arm64 with osx-64.

▶▶ pixi r hello
 WARN pixi::project::environment: osx-arm64 (Apple Silicon) is not supported by the pixi.toml, falling back to osx-64 (emulated with Rosetta)
hello: command not found

Issue description

On macOS, I have dependencies that don't have support for osx-arm64, which is what pixi determines my platform to be. So I have to manually fallback to osx-64. This poses no problems for installing pixi environments, however tasks are not recognized or run.

Expected behavior

After switching "osx-arm64" to "osx-64" in the pyproject, i.e.

[tool.pixi.project]
channels = ["conda-forge"]
platforms = ["osx-64"]

I expect the task to be recognized and run:

▶▶ pixi r hello
✨ Pixi task (hello in default): echo hi
hi

[jjjermiah]

if i understand correctly, you are switching the value of the [platforms] field.

Instead, you should have all platforms listed that you expect the project to work on.

There was a short discussion on discord that also explains this a bit.

So, after you initialize your project successfully and the task you add works, try running:

pixi project platform add osx-64

instead of replacing the platform in the project.

your platform field should be

[tool.pixi.project]
channels = ["conda-forge"]
platforms = [ "osx-arm64", "osx-64"]

Then pixi should solve the environment for all platforms (even the platform thats not your computer)

• you might need to run pixi install for it to do the solving
• this should update the pixi.lock file and the environments will be solved for all platforms
• when the project is then transferred from your M3 Macbook (osx-arm64) to a Intel Macbook (osx-64), then pixi will recognize that the project is configured for that OS as well

[ruben-arts]

@jjjermiah you are correct, however this will not work because of the case @ekiefl describes where he can not install for osx-arm64 because the packages are not available for it.

We've got some code to get the "best" platform which is why you can install osx-64 on osx-arm64 but we indeed missed fixing that for all code, apart from installation.

We should use the following function in more places!

pixi/src/project/environment.rs

Lines 105 to 144 in 2337654

	/// Returns the best platform for the current platform & environment.
	pub fn best_platform(&self) -> Platform {
	let current = Platform::current();
	// If the current platform is supported, return it.
	if self.platforms().contains(&current) {
	return current;
	}
	static WARN_ONCE: Once = Once::new();
	// If the current platform is osx-arm64 and the environment supports osx-64, return osx-64.
	if current.is_osx() && self.platforms().contains(&Platform::Osx64) {
	WARN_ONCE.call_once(|| {
	let warn_folder = self.project.pixi_dir().join(consts::ONE_TIME_MESSAGES_DIR);
	let emulation_warn = warn_folder.join("macos-emulation-warn");
	if !emulation_warn.exists() {
	tracing::warn!(
	"osx-arm64 (Apple Silicon) is not supported by the pixi.toml, falling back to osx-64 (emulated with Rosetta)"
	);
	// Create a file to prevent the warning from showing up multiple times. Also ignore the result.
	fs::create_dir_all(warn_folder).and_then(|_| {
	std::fs::File::create(emulation_warn)
	}).ok();
	}
	});
	return Platform::Osx64;
	}
	if self.platforms().len() == 1 {
	// Take the first platform and see if it is a WASM one.
	if let Some(platform) = self.platforms().iter().next() {
	if platform.arch() == Some(Arch::Wasm32) {
	return *platform;
	}
	}
	}
	current
	}

[ekiefl]

Hey, just popping in to say thank you for your responsiveness in fixing this issue. I updated our pixi version and no more troubles with osx-arm64 architectures :)

[wolfv]

Awesome :)