Nix is a package manager for Linux and other Unix systems. Builds with Nix 2.30.0 on macOS were executed with elevated privileges (root), instead of the build users. The fix was applied to Nix 2.30.1. No known workarounds are available.
https://github.com/NixOS/nix/security/advisories/GHSA-qc7j-jgf3-qmhg
https://github.com/NixOS/nix/pull/13455
https://github.com/NixOS/nix/pull/13281
https://github.com/NixOS/nix/commit/e2ef2cfcbc83ea01308ee64c38a58707ab23dec3