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.