`pixi unpack` in a different platform, what's the limitation?

[awesomebytes]

Hello,
I am playing with re-packaging into a squashfs file a pixi unpack-ed .tar, and it works nicely, but, I would like to package for other archs (which I can pixi pack), but I can't pixi unpack.

I wonder what is the reason for this limitation?

Thank you!

[awesomebytes]

I commented out the check for the platform and tried to unpack and it worked fine, I could unpack in linux-64 and transfer the unpacked environment to linux-aarch64 and use it without issues.

Would you consider changing the behavior of the program to either just remove the check, or, change it to a warning print?

Context: I am packaging a pixi workspace into a squashfs file that's "ready to mount". So I need to be able to unpack to different platforms, so the file is ready to be used without the deploying side needing to unpack or extract it.

[awesomebytes]

I now see that I could alternatively use conda or mamba to extract from your README, however, I don't know if they also do platform checks (and I like the simplicity and how lean pixi pack/unpack is). I may give it a check later, although the modified pixi unpack works well for me for now.

[pavelzw]

There are two reasons for this:

1. on platforms with case-insensitive file systems (windows, macOS), unpacking/installing case-sensitive files (Avoid case-sensitive contents (e.g. WSL on windows)? conda-forge/ncurses-feedstock#73) can lead to errors while installing.
2. the environment will likely not be executable on the target system if it was packaged for a different environment

If you are using something like Rosetta 2 and want to install a osx-64 environment on an osx-arm64 machine, you should be able to run the osx-64 version of pixi-unpack and it should not throw an error.

The current error message

pixi-pack/src/unpack.rs

Lines 152 to 154 in 75ee03e

	if metadata.platform != Platform::current() {
	anyhow::bail!("The pack was created for a different platform");
	}

is just for validation and not necessarily needed. In which use case do you want to install an environment on an incorrect target platform?

[pavelzw]

Context: I am packaging a pixi workspace into a squashfs file that's "ready to mount". So I need to be able to unpack to different platforms, so the file is ready to be used without the deploying side needing to unpack or extract it.

Fair enough. I think a flag to disable the failing behavior would be possible. I'm personally am also interested in such a tool like you described but in order to add it to pixi-pack, I would like it to work for all platforms (including macOS and windows where the squashfs approach is difficult...)

Would an additional flag --install-to-incompatible-target that skips the errors be enough? Daniel Elsner (@delsner) what do you think of this approach?

[awesomebytes]

Would an additional flag --install-to-incompatible-target that skips the errors be enough?

That would work nicely, yeah! Maybe something like --allow-incompatible-target or --disable-platform-check.