jpetrucciani/nix

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hms and hmx ​

mods/hms.nix defines the repo's preferred rebuild helpers.

These are convenience wrappers for people already using this repo day to day. If you are only exploring, the plain nix build .#... commands in Daily Workflows are the simpler starting point.

What Gets Exposed ​

  • hmx.<host>, host-specific scripts with build, diff, and switch actions for both NixOS and nix-darwin machines.
  • hms, a helper that pulls the repo and runs one of those actions for the current machine.

Calling either script without an action is equivalent to switch, so existing hms and direct hmx.<host> usage keeps working.

Behavioral Notes ​

  • build builds the system configuration and prints its store path without activating it.
  • diff builds the system configuration, then uses nvd diff to show system closure changes.
  • On NixOS, diff also runs switch-to-configuration dry-activate to show the systemd units and activation work that a switch would perform.
  • On nix-darwin, diff also lists changed launchd plist definitions. nix-darwin does not provide an activation planner equivalent to NixOS dry-activate.
  • switch shows the nvd diff, updates the system profile, and activates the configuration.
  • Supports forced switching with POG_FORCE=1.
  • On NixOS, POG_BOOT_ONLY=1 updates the system profile but runs switch-to-configuration boot instead of switch.
  • Handles both NixOS and darwin activation flows.

Typical Usage ​

bash
# build the current machine without activating it
hms build

# preview package and service changes for the current machine
hms diff

# switch the current machine using the repo's preferred helper
hms

# preview a specific host through its hmx output
$(nix build --no-link --print-out-paths --extra-experimental-features nix-command --extra-experimental-features flakes .#hmx.<host>)/bin/switch diff

# build or switch that host with the same wrapper
$(nix build --no-link --print-out-paths --extra-experimental-features nix-command --extra-experimental-features flakes .#hmx.<host>)/bin/switch build
$(nix build --no-link --print-out-paths --extra-experimental-features nix-command --extra-experimental-features flakes .#hmx.<host>)/bin/switch switch

Source ​