Exclude `.pixi` from macOS Time Machine backups

[abey79]

Problem description

The .pixi directory can become sizeable with large project (13GB for https://github.com/rerun-io/rerun), but is not excluded by default from macOS Time Machine backups, contrary to, say, Cargo's target directory:

❯ tmutil isexcluded target
[Excluded]  /Users/hhip/src/rerun/target

❯ tmutil isexcluded .pixi
[Included]  /Users/hhip/src/rerun/.pixi

❯ tmutil isexcluded .pixi/envs
[Included]  /Users/hhip/src/rerun/.pixi/envs

It would be great if pixi would have the same behaviour.

This Cargo PR may inform a possible implementation:

• Fix excluding target dirs from backups on OSX rust-lang/cargo#7192

Related:

• Create CACHEDIR.TAG file in pixi directories #1904
• Place CACHEDIR.TAG in .pixi/envs (and similar directories) #2207

Unfortunately, Time Machine doesn't recognise CACHEDIR.TAG, so this approach is not sufficient.