These steps help you set up the Nix package manager with support for a experimental more user-friendly command language and a defined package format called flakes that makes it easier to create builds in a strictly determined environment, so that they create the same outputs on various machines or in CI.

To install Nix, please follow the instructions at https://nixos.org/download.html, since they are quite good.

If you want to know more before installing you can read the install section in the Nix manual directly.

You might have to re-open your terminals, restart your graphical session or even reboot after this step.

Recent releases of Nix already ship with the required code for flakes, but leave them behind a feature flag that you have to enable.

To enable them, you have to add the following lines to /etc/nix/nix.conf

experimental-features = nix-command flakes

and on a multi-user install (invoked with --daemon) restart the nix daemon so it can pick up the newly set experimental options.

systemctl restart nix-daemon.service

The following command should now give similar output.

$ nix flake --help

Usage: nix flake COMMAND FLAGS... ARGS...

Common flags:

Available commands:
  archive      copy a flake and all its inputs to a store
  check        check whether the flake evaluates and run its tests
  clone        clone flake repository
  info         list info about a given flake
  init         create a flake in the current directory from a template
  list-inputs  list flake inputs
  new          create a flake in the specified directory from a template
  show         show the outputs provided by a flake
  update       update flake lock file

Note: this program is EXPERIMENTAL and subject to change.