What the heck is /pkg?

30 points by trousers

tbodt

My /pkg contains something that at first glance almost looks like a nix store

env/
- global -> /pkg/inv/envs/v2udgbuajc4c6qrhdqmoab3kkiymxr6xchez3ylklel5wffdwbca
etc/
inv/
- envs/
  - v2udgbuajc4c6qrhdqmoab3kkiymxr6xchez3ylklel5wffdwbca/
- pkgs/
var/

Curiously it was created about a week after /etc/paths.d/10-pmk-global. I just deleted it all and now I'm kinda hoping it will reappear so I can track down the process or framework behind it.

...pmk could be 'package management kit'?

WeetHet

It's a CAS that seems to store cryptexes, see /private/var/db/com.apple.security.cryptexd/pkg for the backing store. AFAIK cryptexes are required to be signed and everything so I don't think this can be anywhere close to the openness of Nix

kwas

It’s also not clear what the “pmk” in /etc/paths.d/10-pmk-global refers to.

PathManagamentKit

nishnash

Now in macOS 27.0, there’s a new 10-pmk-global file 1 which adds /pkg/env/global/bin to the PATH list.

I’ve found this in 26.5.2, so it predates 27.0

pocket_walrus

It seems like it was first introduced in 26.4 (released in March 2026): https://eclecticlight.co/2026/09/19/macos-tahoe-26-4-changed-boot-volume-structure