downloading Nix 2.1.1 binary tarball for x86_64-darwin from 'https://nixos.org/releases/nix/nix-2.1.1/nix-2.1.1-x86_64-darwin.tar.bz2' to '/var/folders/3b/kr4sj8xj633_b6_b13s7vy440000gn/T/nix-binary-tarball-unpack.XXXXXXXXXX.DwgRkgVe'...
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 28.8M  100 28.8M    0     0  1944k      0  0:00:15  0:00:15 --:--:-- 1921k
Note: a multi-user installation is possible. See https://nixos.org/nix/manual/#sect-multi-user-installation
performing a single-user installation of Nix...
directory /nix does not exist; creating it by running 'mkdir -m 0755 /nix && chown allen /nix' using sudo
copying Nix to /nix/store...................................
initialising Nix database...
error: cannot connect to daemon at '/nix/var/nix/daemon-socket/socket': No such file or directory
/var/folders/3b/kr4sj8xj633_b6_b13s7vy440000gn/T/nix-binary-tarball-unpack.XXXXXXXXXX.DwgRkgVe/unpack/nix-2.1.1-x86_64-darwin/install: unable to register valid paths