Nix disappeared from my Mac
If it looks like Nix is suddenly uninstalled from your macOS system, re-running the Determinate installer will bring it back.
The Nix installer from nixos.org is not resiliant to macOS upgrades. Determinate is resiliant to macOS upgrades, and is carefully tested against macOS upgrades before they are released.
Install Determinate
Try installing Determinate, using the Determinate package for macOS.
The Determinate package will upgrade your Nix installation in place, and keep your Nix store and profiles.
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