What is the canonical way of installing Elixir or Erlang > 19 with `nix` on a non-NixOS system?

Question

Please explain it as you would to a 10-year-old, from the point after the Nix package manager is installed on a non-NixOS machine. For example, I am on a Mac, and there isn\

Answer 1

You are on the right track; there is no need to start over.

To install the package from nix repl you can use the :i command.

nix-repl> :i pkgs.beam.packages.erlangR21.elixir

This will install the package into your ~/.nix-profile where it will be in $PATH, so you can call it. It is equivalent to running

nix-env -iA nixpkgs.beam.packages.erlangR21.elixir

nix-store -r (or equivalently, nix-store --realise) is considered a very low-level tool. It can only create a symlink to a package and that is rarely what you want. It doesn't even create a garbage collection root by default, so if you garbage collect, the symlink will become broken.

Although nix-env -iA is a valid way of installing software, you may consider ~/.nix-profile global state and avoid it for that reason. It seems to me like elixir that is more tied to a project, rather than to your user. For example you may want to use distinct versions for some projects and it may make sense to share your development tools with others who work on a project. That is you can use nix-shell for. Here's an example of shell.nix.