Nix Installation Guide: Difference between revisions

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This guide describes various methods for installing Nix.
This guide describes various '''more advanced''' methods for installing [[Nix]] on an ''existing'' operating system. For installation of [[NixOS]], see [[NixOS Installation Guide]].
 
Please take a look at https://nixos.org/download.html first for basic installation instructions and read the relevant section in the Nix manual if you want to know more about how the install process works: https://nixos.org/manual/nix/stable/#ch-installing-binary.


== Single-user install ==
== Single-user install ==


To install Nix from any Linux distribution, use the following two commands. (Note: This assumes you have the permission to use <code>sudo</code>, and you are logged in as the user you want to install Nix for.)
=== Stable Nix ===
 
To install stable Nix from any Linux distribution, use the following two commands. (Note: This assumes you have the permission to use <code>sudo</code>, and you are logged in as the user you want to install Nix for.)


<syntaxHighlight lang="console">
<syntaxHighlight lang="console">
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</syntaxHighlight>
</syntaxHighlight>


Then don't forget to run the command provided at the end of the installation script to make nix available in your system:
Then don't forget to reboot or run the command provided at the end of the installation script to make nix available in your system:
<syntaxHighlight lang="console">
<syntaxHighlight lang="console">
$ source $HOME/.nix-profile/etc/profile.d/nix.sh
$ source $HOME/.nix-profile/etc/profile.d/nix.sh
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You may want to put this file directly in your ~/.bashrc or similar, so Nix would be available in any newly created shell.
You may want to put this file directly in your ~/.bashrc or similar, so Nix would be available in any newly created shell.
When using another shell like [https://fishshell.com Fish], you should ignore the previous procedure and use the [https://github.com/jorgebucaran/fisher Fisher] plugin [https://github.com/lilyball/nix-env.fish Nix-env].


After that being done, you can use all Nix commands as a normal user without any special permissions (for example by using <code>sudo</code>).
After that being done, you can use all Nix commands as a normal user without any special permissions (for example by using <code>sudo</code>).


==== User namespaces ====
==== Troubleshooting ====
 
===== User namespaces =====
If the installation fails with the following error:
If the installation fails with the following error:
<pre>
<pre>
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enabled by default on Linux which requires user namespaces.
enabled by default on Linux which requires user namespaces.
If possible enable them; the procedure depends on the distribution. In last resort, you can disable the sandbox: create the file <code>~/.config/nix/nix.conf</code> and include the line <code>sandbox = false</code>.
If possible enable them; the procedure depends on the distribution. In last resort, you can disable the sandbox: create the file <code>~/.config/nix/nix.conf</code> and include the line <code>sandbox = false</code>.
=== Unstable Nix ===
To install unstable Nix, you can use the [https://github.com/numtide/nix-unstable-installer unofficial installer by @numtide]. Instructions are available in the README of the repository.


== Nix store on an unusual filesystem ==
== Nix store on an unusual filesystem ==
=== Case insensitive filesystem on Linux ===
=== Case insensitive filesystem on Linux ===
Most Linux filesystems are case sensitive. If your nix store is on a case insensitive filesystem like CIFS on Linux, derivation outputs cannot contain two files differing only in case in the same directory. Nix can work around this by adding <code>use-case-hack = true</code> to your nix configuration (<code>/etc/nix/nix.conf</code> for a multi-user-install or <code>~/.config/nix/nix.conf</code> otherwise). Unfortunately, this will change the hash of some derivations and thus make the binary cache useless.
Most Linux filesystems are case sensitive. If your nix store is on a case insensitive filesystem like CIFS on Linux, derivation outputs cannot contain two files differing only in case in the same directory. Nix can work around this by adding <code>use-case-hack = true</code> to your nix configuration (<code>/etc/nix/nix.conf</code> for a multi-user-install or <code>~/.config/nix/nix.conf</code> otherwise). Unfortunately, this will change the hash of some derivations and thus make the binary cache useless.
=== WSL ===
The same caveats as NFS below apply.


=== NFS ===
=== NFS ===
Without special care, concurrent use of Nix if the nix store is on a NFS filesystem may corrupt Nix's sqlite database.
To prevent this, add <code>use-sqlite-wal = false</code> to your nix configuration and recompile nix with this patch:
<syntaxHighlight lang="diff">
--- a/src/libstore/sqlite.cc
+++ b/src/libstore/sqlite.cc
@@ -28,7 +28,7 @@ namespace nix {
SQLite::SQLite(const Path & path)
{
    if (sqlite3_open_v2(path.c_str(), &db,
-            SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0) != SQLITE_OK)
+            SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, "unix-dotfile") != SQLITE_OK)
        throw Error(format("cannot open SQLite database '%s'") % path);
}</syntaxHighlight>


(source: [https://github.com/NixOS/nix/issues/2357 this issue])
With a Nix store residing on an NFS filesystem, concurrent use of Nix may corrupt Nix's sqlite database. To prevent this, set <code>use-sqlite-wal = false</code>. Since [https://github.com/NixOS/nix/pull/5475 nix/pull/5475 nix/pull/5475] and it's backports to the stable branches, a patch that was previously described in this wiki is no longer needed for using Nix on WSL (Windows' Subsystem for Linux) and NFS filesystems.
 
Nix is hard to build by hand, but you can still use vanilla nix without concurrent use, so you can install nix with a NFS store as follows:
* Install nix with the vanilla binary installer
* Create a file <code>~/.config/nixpkgs/config.nix</code> as follows, and place the patch above alongside it.
<syntaxHighlight lang="nix">
{
        packageOverrides = pkgs: {
                nix = pkgs.nix.overrideAttrs (old: {
                                patches = (old.patches or []) ++ [ ./nfs.patch ];
                      });
        };
}
</syntaxHighlight>
* Run <code>nix-env -iA nixpkgs.nix</code> to compile and install the new, patched nix.
* From then on, you can use nix concurrently without risk of corrupting the sqlite database.


== Installing without root permissions ==
== Installing without root permissions ==
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[https://github.com/nix-community/nix-user-chroot nix-user-chroot] is the preferred method to install use nix on systems without <code>/nix</code>. It also requires user namespaces to be enabled on the system.
[https://github.com/nix-community/nix-user-chroot nix-user-chroot] is the preferred method to install use nix on systems without <code>/nix</code>. It also requires user namespaces to be enabled on the system.
<code>nix-user-chroot</code> will create an environment in which you can bind mount an directory to <code>/nix</code>.
<code>nix-user-chroot</code> will create an environment in which you can bind mount a directory to <code>/nix</code>.
The mountpoint will be only visible within this environment.
The mountpoint will be only visible within this environment.


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Note that you can only use Nix and the installed programs within the shell started by PRoot.
Note that you can only use Nix and the installed programs within the shell started by PRoot.
==== Troubleshooting ====
PRoot uses ptrace to capture and modify system calls. It happens that new system calls are created which proot does not shim yet. If you run into issues, check if:
* you have the latest proot
* the system calls being used are supported by proot (TODO: how to list and diff with sysnums.list?)
Since ptrace only allows one tracer to attach to a process at a time, you cant strace your process while in proot. One suggestion is to strace your application outside of proot to find what system calls are used. Alternatives may be tracing with bpftrace or trace-cmd/ftrace. (This is not elaborated on here because the author doesn't know how to do it.)
A table of system calls supported by proot-rs, which is not the same as proot, can be found at https://github.com/proot-me/proot-rs/wiki/Translation-of-system-calls .
As of PRoot 5.3.1 and 2022-Oct-24, PRoot doesn't support faccess2, which is invoked in glibc by bash through coreutils test. This makes the `[ -w /nix ]` expression fail incorrectly in the nix installer script. This can be worked around with this patch: https://github.com/proot-me/proot/pull/338 or <code>nix-shell -I nixpkgs=channel:nixos-unstable -p '(proot.overrideAttrs (o: { patches = [ (builtins.fetchurl "https://patch-diff.githubusercontent.com/raw/proot-me/proot/pull/338.patch" ) ]; }))'</code>


=== nix 2.0's native method ===
=== nix 2.0's native method ===
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You can make all nix commands use the alternate store by specifying it in `~/.config/nix/nix.conf` as <code>store = /home/USERNAME/my-nix</code>.
You can make all nix commands use the alternate store by specifying it in `~/.config/nix/nix.conf` as <code>store = /home/USERNAME/my-nix</code>.
== Installing on Debian Using APT ==
If you are using Debian (or a Debian-based distro) you can install Nix with the APT package manager. Some users may prefer using APT when modifying their system. The package named <code>nix-setup-systemd</code> will set up a multi-user Nix installation and run <code>nix-daemon</code> via <code>systemd</code>. To install:
<syntaxHighlight lang="console">
$ sudo apt install nix-setup-systemd
</syntaxHighlight>
After installing, you should read <code>/usr/share/doc/nix-bin/README.Debian</code>. In particular, you will need to add your user to the <code>nix-users</code> group in order to use the daemon:
<syntaxHighlight lang="console">
$ sudo /sbin/adduser $USER nix-users
</syntaxHighlight>
Note that in Debian [https://packages.debian.org/bookworm/nix-setup-systemd Bookworm] <code>/etc/nix/nix.conf</code> will contain <code>sandbox = false</code>, but in Debian [https://packages.debian.org/trixie/nix-setup-systemd Trixie], sandbox mode is enabled by default. (See the Changelog for details.)
=== Configure user and/or desktop ===
To start installed nix applications from the command line, add the <code>~/.nix-profile/bin</code> to <code>PATH</code>.
To give the Desktop access the nix application data add the <code>~/.nix-profile/share</code> to <code>XDG_DATA_DIRS</code>.
For example include the following snippet in <code>~/.profile</code> of the user:
<syntaxHighlight lang="console">
### set PATH so it includes user's nix bin if it exists
if [ -d "$HOME/.nix-profile/bin" ] ; then
    PATH="$HOME/.nix-profile/bin:$PATH"
fi
### set XDG_DATA_DIR so it includes user's nix share if it exists
if [ -d "$HOME/.nix-profile/share" ] ; then
    XDG_DATA_DIRS="$HOME/.nix-profile/share:$XDG_DATA_DIRS"
fi
</syntaxHighlight>
Used source: https://imranmustafa.net/nix-on-debian/
=== Troubleshooting ===
During the <code>nix-build</code> command following the https://nix.dev/tutorials/nixos/nixos-configuration-on-vm#creating-a-qemu-based-virtual-machine-from-a-nixos-configuration
an error could occur like:
<code>...linux-6.12.39-modules-shrunk/lib' is not in the Nix store</code> whilst the directory is present in the <code>/nix/store/</code> directory.
A possible solution is to upgrade nix and nix-daemon applications because the distributed nix version is older, quite older with Debian [https://packages.debian.org/bookworm/nix-setup-systemd Bookworm], than the current nix version:
1) Define the config at <code>~/.config/nixpkgs/config.nix</code>:
<syntaxHighlight lang="console">
with (import <nixpkgs> {});
{
  packageOverrides = pkgs: with pkgs; {
    userPackages = buildEnv {
      extraOutputsToInstall = [ "doc" "info" "man" ];
      name = "user-packages";
      paths = [
        nix
      ];
    };
  };
}
</syntaxHighlight>
To upgrade nix:
<syntaxHighlight lang="console">
nix-env --install --attr nixpkgs.userPackages --remove-all
</syntaxHighlight>
Logout and login the user to see the effects.
2) To use the upgraded <code>nix-daemon</code> application from the previous step in the <code>nix-daemon.service</code>, add a drop-in config file <code>override.conf</code> in <code>/etc/systemd/system/nix-daemon.service.d/</code>:
<syntaxHighlight lang="console">
[Service]
ExecStart=
ExecStart=@/home/myuser/.nix-profile/bin/nix-daemon nix-daemon --daemon
</syntaxHighlight>
Restart the <code>nix-daemon.service</code>
Used source: https://blog.koch.ro/posts/2024-01-16-using-nix-package-manager-in-debian.html




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Because there is no officially produced ARMv7l installer, this page describes how to build your own: [[Nix_on_ARM]].
Because there is no officially produced ARMv7l installer, this page describes how to build your own: [[Nix_on_ARM]].
[[Category:nix]]
[[Category:Cookbook]]