feature: try to add nix-darwin support

[n8henrie]

Merges work by @montchr, @cmhamill, and @rtimush and rebases on main.

• fixes darwin build failure: system.activationScripts.users.deps does not exist #60
• fixes Add darwinModules for use with nix-darwin #120
• closes Add support for nix-darwin #107

[ryantm]

Yay passing tests! I don't have a system to try this on. If you do, please chime in if it works for you.

[ryantm]

Code overall looks good to me and I'm basically ready to merge. I tested the integration test fails if I expect a different decrypted file contents.

It would be nice to get one more nix-darwin user to sanity check this before merging, but if we don't get one by the end of the week lets

[rtimush]

I tested this PR and it all worked for me 👍
The only minor thing was that this output was a bit too verbose during darwin-rebuild switch:

[n8henrie]

I'll capture that output, good point.

Will do a little more testing this morning.

[ryantm]

from https://app.element.io/#/room/#agenix:nixos.org

[n8henrie]

Few minor changes incoming.

[n8henrie]

@ryantm What would you think about using apfs instead of hfs here? APFS is the Apple-preferred filesystem these days, should be compatible with MacOS 10.13+ (released ~2017).

EDIT: For example the nix store is APFS on my M1 Mac (is it hfs on older macs)?

[ryantm]

@n8henrie I know almost nothing about MacOS file systems. I haven't used a Mac for over 16 years. Maybe you can ping the other people that were trying to get nix-darwin support?

[n8henrie]

Looks like using mount_apfs won't let us use the mask flag (-m=0751) that we're currently using on hfs. I'm not sure how important this is, so I just left it as hfs for now.

[n8henrie]

Integration tests are now failing, I think due to removal of the activation scripts.

EDIT: Nope, passing now and without the activation scripts.

[n8henrie]

Gah, older macos doesn't like the diskutil, which had a more readable size for the ramdisk. Fix incoming.

[n8henrie]

Ok, I think this is ready to merge (would be great if 1 more nix-darwin user can pull and test). Tests passing, working on reboot with my system.

[ryantm]

@rtimush up for another try?

[rtimush]

@rtimush up for another try?

Tried and everything worked fine for me 👍