nix: Add macOS launchd service to hm-module module

[meck]

Home manager has the possibility to run macOS launchd services. These are automatically disabled when running on linux.

[feschber]

Would be a good addition to have a launchd service definition in general. (#49)

Same as with the example config, I would prefer to have this in a central location (e.g. service/macos-launchd/lan-mouse.xml) and then referenced from the nix config.

I'm not to familiar with macos, so let me know if this could work.

[meck]

Not quite sure, I'm not really a mac dev either. Pulling an externally defined launchd unit to nix would be complicated as it would need some editing wrt paths and so on. It's basically the same situation as the systemd unit that currently is defined in hm-module.nix separate from the one in service/lan-mouse.service

Regarding providing a general launchd unit outside of nix as a plain file there are some issues as well, the path to the executable needs to be absolute, so might need some editing. The canonical "mac" way would be to crate an app bundle (maybe (cargo-bundle)[https://github.com/burtonageo/cargo-bundle] could be used) and include the unit there and install at runtime.

[feschber]

Not quite sure, I'm not really a mac dev either. Pulling an externally defined launchd unit to nix would be complicated as it would need some editing wrt paths and so on. It's basically the same situation as the systemd unit that currently is defined in hm-module.nix separate from the one in service/lan-mouse.service

Regarding providing a general launchd unit outside of nix as a plain file there are some issues as well, the path to the executable needs to be absolute, so might need some editing. The canonical "mac" way would be to crate an app bundle (maybe (cargo-bundle)[https://github.com/burtonageo/cargo-bundle] could be used) and include the unit there and install at runtime.

Okay I see this is something that will go on the list then.