[Nix-dev] NIX_REMOTE and nixos-rebuild

[Lluís Batlle i Rossell]

In nixos, the root user shell goes with NIX_REMOTE=

The rest of the users go with NIX_REMOTE=daemon.

Nevertheless, nixos-rebuild has the line: NIX_REMOTE=${NIX_REMOTE:-daemon}
Which means, that if NIX_REMOTE is null or unset, it sets it to daemon.

Doesn't that mean, that in any case it will end up as daemon? What is the
difference between that line and NIX_REMOTE=daemon?