Setting up and using Nix and rix on Linux and Windows

Windows pre-requisites

If you are on Windows, you need the Windows Subsystem for Linux 2 (WSL2) to run Nix. If you are on a recent version of Windows 10 or 11, you can simply run this as an administrator in PowerShell:

wsl --install

You can find further installation notes at this official Microsoft documentation.

We recommend to activate systemd in Ubuntu WSL2, mainly because this supports other users than root running Nix. To set this up, please do as outlined in the official Microsoft WSL documentation:

# in WSL2 Ubuntu shell

sudo -i
nano /etc/wsl.conf

This will open the /etc/wsl.conf in a nano, a command line text editor. Add the following line:

[boot]
systemd=true

Save the file with CTRL-O and then quit nano with CTRL-X. Then, type the following line in powershell:

wsl --shutdown

and then relaunch WSL (Ubuntu) from the start menu.

Afterwards, you can install Nix like business as usual. You can proceed with the Determinate Systems installer.

Using the Determinate Systems installer

You can use {rix} to generate Nix expressions even if you don’t have Nix installed on your system, but obviously, you need to install Nix if you actually want to build the defined development environment and use them.

Installing (and uninstalling) Nix is quite simple, thanks to the installer from Determinate Systems, a company that provides services and tools built on Nix.

Do not use your operating system’s package manager to install Nix. Instead, simply open a terminal and run the following line (on Windows, if you cannot or have decided not to activate systemd, then you have to append --init none to the command. You can find more details about this on The Determinate Nix Installer page):

curl --proto '=https' --tlsv1.2 -sSf \
    -L https://install.determinate.systems/nix | \
     sh -s -- install

Then, configure the rstats-on-nix binary cache. This will download pre-built binaries of many R packages, significantly speeding up the building process. Many thanks to Cachix for sponsoring the rstats-on-nix cache!

Recommended: Using setup_cachix()

The simplest approach is to use {rix}’s setup_cachix() function from R. First, start R from a Nix shell:

nix-shell -p R rPackages.rix

On first use, this may take a few minutes (up to 5 minutes) as Nix downloads R and required packages. Be patient! Subsequent runs will be instant.

Then run:

rix::setup_cachix()

This configures the cache in ~/.config/nix/nix.conf. You also need to add yourself as a trusted user so Nix allows you to use the cache. Run the following one-liner:

echo "trusted-users = root $USER" | sudo tee -a /etc/nix/nix.custom.conf && sudo systemctl restart nix-daemon

This works for both standard Nix installations and Determinate Nix installations. If you see warnings like ignoring untrusted substituter, this means the trusted-users configuration is not in place.

Alternative: Using the cachix client

Alternatively, you can use the cachix command-line client:

nix-env -iA cachix -f https://cachix.org/api/v1/install
cachix use rstats-on-nix

Note: If you installed Nix using the Determinate Systems installer, this approach will not work because /etc/nix/nix.conf is protected and restored on restart. Use setup_cachix() instead.

NixOS users

If you are using NixOS, the Nix configuration is managed declaratively through your system configuration, so setup_cachix() and cachix use will not work. Instead, add the cache to your configuration.nix:

nix.settings = {
  substituters = [
    "https://cache.nixos.org"
    "https://rstats-on-nix.cachix.org"
  ];
  trusted-public-keys = [
    "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
    "rstats-on-nix.cachix.org-1:vdiiVgocg6WeJrODIqdprZRUrhi1JzhBnXv7aWI6+F0="
  ];
};

If you use Home Manager, add this to your home configuration instead:

nix.settings = {
  substituters = [
    "https://rstats-on-nix.cachix.org"
  ];
  trusted-public-keys = [
    "rstats-on-nix.cachix.org-1:vdiiVgocg6WeJrODIqdprZRUrhi1JzhBnXv7aWI6+F0="
  ];
};

Then rebuild your system with sudo nixos-rebuild switch (or home-manager switch for Home Manager).

On Linux, once Nix is installed, all the software that will be installed through Nix will be saved to the /nix directory on the root partition. It is common for Linux users to have a separate partition for /, which may be small. Complete development environments built with Nix can take up much space, so if the available space on your root partition is limited, we advise you to mount the /nix folder on another partition with more space (for example, a secondary hard drive). For this, edit /etc/fstab and add the following line at the end:

/home/path_to/nix /nix none bind 0 0

This will map /nix to /home/path_to/nix which can be on a larger partition. If you have enough space on your root partition, you can ignore the above instructions.