Nix
Nix is a purely functional package manager that aims to make package management reliable and reproducible.
Installation
There are three choices for installing Nix: the native Arch Linux package, the upstream installation script officially supported by Nix, and the "Zero to Nix" script provided by Determinate Systems, a company providing third party support for Nix.
Native
Upstream installation script
Download the file with curl --proto '=https' --tlsv1.2 -sSfL https://nixos.org/nix/install -o nix-install.sh, view it: less ./nix-install.sh, and run the script ./nix-install.sh --daemon to start Nix installation.
curl some-url | sh, as the Nix documentation suggests, is considered as a security risk, because it executes unknown code. Therefore it is recommended to manually download the script and check it, before executing it.Zero to Nix installation script
For an easier and less complicated Nix setup you can use the setup from Determinate Systems. Download the file with curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix -o nix-install.sh, view it: less ./nix-install.sh, and run the script sh ./nix-install.sh install to start the installation.
curl some-url | sh, as Determinate Systems suggests, is considered as a security risk, because it executes unknown code. Therefore it is recommended to manually download the script and check it, before executing it.sh ./nix-install.sh install --diagnostic-endpoint="".For more information see the manual from Determinate Systems.
Configuration
To have the Nix daemon launched at boot time, enable nix-daemon.service.
Add required users to the nix-users group in order to access the daemon socket.
Add a channel and update it.
$ nix-channel --add https://nixos.org/channels/nixpkgs-unstable $ nix-channel --update
Usage
With the shell configured, the following should install hello into your updated PATH: /nix/store/[hash]-hello-[version]/bin/hello.
If you installed Nix from the official repositories, you must add the ~/.nix-profile/bin directory to your PATH manually.
$ nix-env -iA nixpkgs.hello
Run hello and make sure it is in the right PATH. If it works, you can remove it simply by
$ nix-env --uninstall hello
Or you can check the list of installed program by (q stands for query)
$ nix-env -q
You can also check generations by
$ nix-env --list-generations
Check more details in the nix-env(1) manual.
Tips and tricks
Max jobs
By default, nix only uses one builder. The following will allow nix to use as many jobs as the number of CPUs:
/etc/nix/nix.conf
max-jobs = auto
Graphical acceleration
To run OpenGL and Vulkan applications, use NixGL.
Desktop integration
For integrating Nix applications with your desktop environment, add the ~/.nix-profile/share directory to your $XDG_DATA_DIRS, for instance using export XDG_DATA_DIRS=$HOME/.nix-profile/share:$XDG_DATA_DIRS.
Zsh integration for nix-shell
nix-shell starts Bash by default. zsh-nix-shell lets you use zsh as the default shell in a nix-shell environment. Some prompt plugins such as powerlevel10k and pure provide a nix-shell indicator.
Command completion
Zsh
nix-zsh-completions provides Zsh completions for nix commands such as nix-env and nix-shell.
Troubleshooting
Permission denied
Running nix repl or nix-env -u as user produces
cannot connect to daemon at '/nix/var/nix/daemon-socket/socket: permission denied
If you just installed nix, you need to reboot.
Too many open files
Some builds may run into an error such as
error: opening directory '/nix/store/...': Too many open files
Edit nix-daemon.service and increase the file limit
[Service] LimitNOFILE=65536
Warning message about root user channels
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
If the above message shows up when using Nix, the root user will need to update their channels.
# nix-channel --update
warning: Nix search path entry '/nix/var/nix/profiles/per-user/<USER>/channels' does not exist, ignoring
See FS#78828. Alternatively, you can use the #Upstream installation script, which does not exhibit the issue.
error: file 'nixpkgs' was not found in the Nix search path (add it using $NIX_PATH or -I)
See FS#78828. Alternatively, you can use the #Upstream installation script, which does not exhibit the issue.
Sandbox build issues
Other sandbox issues
error: while setting up the build environment: mounting /proc: Operation not permitted error: program '/usr/bin/nix-env' failed with exit code 1
1: package 'utils' in options("defaultPackages") was not found
2: package 'stats' in options("defaultPackages") was not found
Error: .onLoad failed in loadNamespace() for 'utils', details:
call: system(paste(which, shQuote(names[i])), intern = TRUE, ignore.stderr = TRUE)
error: cannot popen '/nix/store/fnkvlbls29d01jcx3wsdnhykyrl7087r-which-2.21/bin/which 'uname' 2>/dev/null', probable reason 'Cannot allocate memory'
The issue is known upstream: #2311, #3000, and #4636.
nixpkgs expects to be built with the sandbox on.The most common fix is to disable sandboxing in the configuration file, then Restart the nix-daemon service.
/etc/nix/nix.conf
# disable sandboxing sandbox = false
Locale warnings
The Nix wiki recommends running export LOCALE_ARCHIVE=/usr/lib/locale/locale-archive. Alternatively, export the environment variable LC_ALL=C.