Installing and Configuring Nix
Install Nix by following the official installation instructions,
or by consulting your system's own package manager.
I use Arch Linux, so pacman -Syu nix is all I needed to do.
Test that your installation is working:
$ nix --version
nix (Nix) 2.11.0
...and that you can install packages, e.g. by spawning an ephemeral shell that has access
to the hello package:
$ # Spawning a shell with the hello package:
$ nix-shell --packages hello
[nix-shell:~]$ # Running the hello binary from inside a shell:
[nix-shell:~]$ hello
Hello, world!
[nix-shell:~]$ # The binary resides in the Nix Store:
[nix-shell:~]$ which hello
/nix/store/g2m8kfw7kpgpph05v2fxcx4d5an09hl3-hello-2.12.1/bin/hello
[nix-shell:~]$ exit
$ # No more hello binary outside of the shell:
$ which hello
hello not found
Nixpkgs provides a lot of packages; you can either search the package index on the web or locally:
$ nix-env --query --available -P 'agdaWithPackages'
nixpkgs.agda agdaWithPackages-2.6.2.2
The above says that the package agdaWithPackages is available under the name nixpkgs.agda.
The Nix command line tools operate on nixpkgs by default, so running Agda is as simple as that:
$ nix-shell --packages 'agda' --run "agda --version"
Agda version 2.6.2.2