Cannot install nix packages on Mac because .nix-defexpr doesn't exists

Question

I have installed Nix on a Mac OSX (v 10.9.2) but anytime I try to run any command I get this message:

error: getting information about '/Users/myuser/.nix-defexpr': No such file or directory

This seems related with the absence of channels properly defined, but I don't know how to create them. Other nix installations on Gnu/Linux automatically do that and running .nix-env --update nixpkgs gives me ./nix-channel: unable to check 'https://nixos.org/channels/nixpkgs-unstable, but I can browse that address from Firefox/Brave.

BTW, login out a re-login doesn't make any nix commands available from command prompt, so I need to run them from ~/.nix-profile/bin/.

Any clue about how to solve it?

Answer 1

This is more of a comment but an answer but I don't have enough reputation to do that. Hopefully this will suffice.

I would guess that something went funny with your installation of nix:

• .nix-defexpr dir is the locations of the expressions you download from a channel. So if that's missing then you won't get much joy.
• .nix-profile/bin: iirc there's a small shell script that gets sourced from your .bash-profile and adds .nix-profile to your $PATH. That also should get added to .bash-profile at installation.

If it's feasible for you to simply reinstall nix using the nix install script curl https://nixos.org/nix/install | sh (link) that should be the easiest option.