feat: new subcommand to split lockfile

[gzm55]

Close #4015

This pr implements a new subcommand pixi workspace export split-lockfile, which splits the pixi.lock into a specified base folder. The packages of each environment and platform are written into /{platform}/{environment}.lock. The channels, solve options and pypi indexes of each environment are kept in the output files.

[gzm55]

@baszalmstra any suggestion about this pr?

[gzm55]

TRY 1 SLOW [>720.000s] pixi::integration_rust install_tests::minimal_lockfile_update_pypi

@baszalmstra there's an unrelated slow IT case timing out.

[nichmor]

Let's also add a test for this feature

[gzm55]

Let's also add a test for this feature

OK

[ruben-arts]

I don't get the selling point for this feature. The lockfiles cannot be used stand alone and no other tool then pixi can install them due to the pypi and source dependencies.

Could you explain why this feature will be useful to the users?

[gzm55]

I don't get the selling point for this feature. The lockfiles cannot be used stand alone and no other tool then pixi can install them due to the pypi and source dependencies.

Could you explain why this feature will be useful to the users?

@ruben-arts The rattler lockfiles format is powerful and could be standard lock file in conda ecosystem. It also evolves (conda/rattler#1214) with many new improvements. Stand alone lockfiles can integrate with other conda tools easily and explicitly. pixi and rattler can introduce many fancy features for lockfiles to build packages or run tasks, whereas the exported lean rattler lockfiles can also be loaded by other tools to describe a conda prefix precisely. Some tools are under incubation to utilize the lockfiles, e.g. conda-lockfiles and existing pixi extensions. The source dependencies may less supported by other integrating tools, but all-binary environment can be used first.

[gzm55]

Let's also add a test for this feature

@nichmor the test is added.

[Hofer-Julian]

whereas the exported lean rattler lockfiles can also be loaded by other tools to describe a conda prefix precisely

If you are thinking about a common lock file standard, then we are definitely interested. But I don't think we should implement anything before we have a good agreement with other parties how that should look like.

[gzm55]

If you are thinking about a common lock file standard, then we are definitely interested. But I don't think we should implement anything before we have a good agreement with other parties how that should look like.

pr follows the current lock file spec by loading/building/writing lockfiles via functions from rattler, and have no change on the output format. so the output files can be read by the previous listed tools and pixi self.