FAQ: Difference between revisions
imported>Makefu import from nixos-users |
imported>Fadenb m Syntax highlighting + indentation |
||
| Line 15: | Line 15: | ||
If you have a lot of dependencies, you may want to write a nix expression that includes your dependencies so that you can simply use <code>nix-shell</code> rather than writing out each dependency every time or keeping your development environment in your shell history. A minimal example looks like this: | If you have a lot of dependencies, you may want to write a nix expression that includes your dependencies so that you can simply use <code>nix-shell</code> rather than writing out each dependency every time or keeping your development environment in your shell history. A minimal example looks like this: | ||
< | <syntaxhighlight lang="nix"># default.nix | ||
with import | with import <nixpkgs> {}; | ||
stdenv.mkDerivation { | stdenv.mkDerivation { | ||
name = | name = "dev-environment"; # Probably put a more meaningful name here | ||
buildInputs = [ pkgconfig zlib ]; | buildInputs = [ pkgconfig zlib ]; | ||
}</ | }</syntaxhighlight> | ||
=== Why does it work like that? === | === Why does it work like that? === | ||
| Line 27: | Line 27: | ||
== How to keep build-time dependencies around / be able to rebuild while being offline? == | == How to keep build-time dependencies around / be able to rebuild while being offline? == | ||
< | <syntaxhighlight lang="nix"># /etc/nixos/configuration.nix | ||
{ config, pkgs, lib, ... }: | { config, pkgs, lib, ... }: | ||
{ | { | ||
| Line 34: | Line 34: | ||
gc-keep-derivations = true | gc-keep-derivations = true | ||
''; | ''; | ||
}</ | }</syntaxhighlight> | ||
Check 'man configuration.nix' for these options. Rebuild for these options to take effect: | Check 'man configuration.nix' for these options. Rebuild for these options to take effect: | ||
< | <syntaxhighlight lang="bash">nixos-rebuild switch</syntaxhighlight> | ||
List all store paths that form the system closure and realise them: | List all store paths that form the system closure and realise them: | ||
< | <syntaxhighlight lang="bash"> | ||
nix-store -qR $(nix-instantiate /etc/nixos/nixos -A system) | xargs nix-store -r | |||
warning: you did not specify `--add-root'; the result might be removed by the garbage collector | |||
< | |||
<build output and list of successfully realised paths> | |||
</syntaxhighlight> | |||
Repeat for your user and further profiles: | Repeat for your user and further profiles: | ||
< | <syntaxhighlight lang="bash">nix-store -qR ~/.nix-profile |xargs nix-store -r</syntaxhighlight> | ||
The warning can be ignored for profiles that are listed/linked in ''/nix/var/nix/profiles/'' or one of its subdirectories. | The warning can be ignored for profiles that are listed/linked in ''/nix/var/nix/profiles/'' or one of its subdirectories. | ||
Consult man pages of nix-store and nix-instantiate for further information. | Consult man pages of nix-store and nix-instantiate for further information. | ||
== Why | == Why <hash>-<name> instead of <name>-<hash>? == | ||
For the rare cases where we have to dig into the /nix/store it is more practical to keep in mind the first few letters at the beginning than finding a package by name. In addition, the hash is printed by Nix commands. If you still wonder why, run <code>ls -1 /nix/store | sort -R -t - -k 2 | less</code> in your shell. | For the rare cases where we have to dig into the /nix/store it is more practical to keep in mind the first few letters at the beginning than finding a package by name. In addition, the hash is printed by Nix commands. If you still wonder why, run <code>ls -1 /nix/store | sort -R -t - -k 2 | less</code> in your shell. | ||
| Line 57: | Line 59: | ||
This is what might happen if you don't garbage collect frequently, or if you are testing compilation variants: | This is what might happen if you don't garbage collect frequently, or if you are testing compilation variants: | ||
< | <syntaxhighlight lang="bash"> | ||
q0yi2nr8i60gm2zap46ryysydd2nhzhp-automake-1.11.1/ | |||
vbi4vwwidvd6kklq2kc0kx3nniwa3acl-automake-1.11.1/ | vbi4vwwidvd6kklq2kc0kx3nniwa3acl-automake-1.11.1/ | ||
wjgzir57hcbzrq3mcgxiwkyiqss3r4aq-automake-1.11.1/ | wjgzir57hcbzrq3mcgxiwkyiqss3r4aq-automake-1.11.1/ | ||
| Line 65: | Line 68: | ||
8jij13smq9kdlqv96hm7y8xmbh2c54iy-nixos-build-vms/ | 8jij13smq9kdlqv96hm7y8xmbh2c54iy-nixos-build-vms/ | ||
j714mv53xi2j4ab4g2i08knqr137fd6l-nixos-build-vms/ | j714mv53xi2j4ab4g2i08knqr137fd6l-nixos-build-vms/ | ||
xvs7y09jf7j48p6l0p87iypgpq470jqw-nixos-build-vms/</ | xvs7y09jf7j48p6l0p87iypgpq470jqw-nixos-build-vms/ | ||
</syntaxhighlight> | |||
== I've updated my channel and something is broken, how can I rollback to an earlier channel? == | == I've updated my channel and something is broken, how can I rollback to an earlier channel? == | ||
View the available generations of your channel: | View the available generations of your channel: | ||
< | <syntaxhighlight lang="bash"> | ||
nix-env --list-generations -p /nix/var/nix/profiles/per-user/root/channels | |||
18 2014-04-17 09:16:28 | |||
19 2014-06-13 10:31:24 | 19 2014-06-13 10:31:24 | ||
20 2014-08-12 19:09:20 (current)</ | 20 2014-08-12 19:09:20 (current) | ||
</syntaxhighlight> | |||
To rollback to the previous generation: | To rollback to the previous generation: | ||
< | <syntaxhighlight lang="bash"> | ||
nix-env --rollback -p /nix/var/nix/profiles/per-user/root/channels | |||
switching from generation 20 to 19 | |||
</syntaxhighlight> | |||
To switch to a particular generation: | To switch to a particular generation: | ||
< | <syntaxhighlight lang="bash"> | ||
nix-env --switch-generation 18 -p /nix/var/nix/profiles/per-user/root/channels | |||
switching from generation 20 to 18 | |||
</syntaxhighlight> | |||
== I'm working on a new package, how can I build it without adding it to nixpkgs? == | == I'm working on a new package, how can I build it without adding it to nixpkgs? == | ||
< | <syntaxhighlight lang="bash">nix-build -E 'with import <nixpkgs> { }; callPackage ./mypackage.nix { }'</syntaxhighlight> | ||
You can replace callPackage with callPackage_i686 to build the 32-bit version of your package on a 64-bit system if you want to test that. | You can replace callPackage with callPackage_i686 to build the 32-bit version of your package on a 64-bit system if you want to test that. | ||
| Line 91: | Line 101: | ||
To build a package with -O0 and -g, and without stripping debug symbols use: | To build a package with -O0 and -g, and without stripping debug symbols use: | ||
< | <syntaxhighlight lang="bash">nix-build -E 'with import <nixpkgs> { }; enableDebugging fooPackage'</syntaxhighlight> | ||
== How can I force a rebuild from source even without modifying the nix expression? == | == How can I force a rebuild from source even without modifying the nix expression? == | ||
As root you can run nix-build with the --check flag: | As root you can run nix-build with the --check flag: | ||
< | <syntaxhighlight lang="bash">sudo nix-build --check -A ncdu</syntaxhighlight> | ||
== How can I manage software with nix-env like with configuration.nix? == | == How can I manage software with nix-env like with configuration.nix? == | ||
| Line 103: | Line 113: | ||
<ol style="list-style-type: decimal;"> | <ol style="list-style-type: decimal;"> | ||
<li><p>Create a meta package called ''userPackages'' your ''~/.config/nixpkgs/config.nix'' file with the packages you would like to have in your environment:</p> | <li><p>Create a meta package called ''userPackages'' your ''~/.config/nixpkgs/config.nix'' file with the packages you would like to have in your environment:</p> | ||
< | <syntaxhighlight lang="nix"> | ||
with (import <nixpkgs> {}); | |||
packageOverrides = pkgs: with pkgs; { | { | ||
packageOverrides = pkgs: with pkgs; { | |||
userPackages = buildEnv { | |||
inherit ((import <nixpkgs/nixos> {}).config.system.path) | |||
pathsToLink ignoreCollisions postBuild; | pathsToLink ignoreCollisions postBuild; | ||
extraOutputsToInstall = [ "man" ]; | |||
name = "user-packages"; | |||
paths = [ vim git wget ]; | |||
}; | }; | ||
} | |||
</syntaxhighlight></li> | |||
<li><p>Install all specified packages using this command:</p> | <li><p>Install all specified packages using this command:</p> | ||
< | <syntaxhighlight lang="bash">nix-env -iA userPackages -f '<nixpkgs>'</syntaxhighlight></li></ol> | ||
Now you can add and remove packages from the paths list and rerun nix-env to update your user local packages. | Now you can add and remove packages from the paths list and rerun nix-env to update your user local packages. | ||
| Line 123: | Line 135: | ||
It probably just needs to know where to find the libraries it needs. You can use [https://nixos.org/patchelf.html patchelf] to set the library path and dynamic linker appropriately: | It probably just needs to know where to find the libraries it needs. You can use [https://nixos.org/patchelf.html patchelf] to set the library path and dynamic linker appropriately: | ||
< | <syntaxhighlight lang="nix"> | ||
with import | # mybinaryprogram.nix | ||
with import <nixpkgs> {}; with xlibs; | |||
stdenv.mkDerivation rec { | stdenv.mkDerivation rec { | ||
name = | name = "somename"; | ||
buildInputs = [ makeWrapper ]; | buildInputs = [ makeWrapper ]; | ||
buildPhase = | buildPhase = "true"; | ||
libPath = lib.makeLibraryPath [ libXrandr libXinerama libXcursor ]; | libPath = lib.makeLibraryPath [ libXrandr libXinerama libXcursor ]; | ||
unpackPhase = | unpackPhase = "true"; | ||
installPhase = '' | installPhase = '' | ||
mkdir -p $out/bin | mkdir -p $out/bin | ||
cp ${./mybinaryprogram} $out/bin/mybinaryprogram | cp ${./mybinaryprogram} $out/bin/mybinaryprogram | ||
patchelf \ | patchelf \ | ||
--set-interpreter | --set-interpreter "$(< "$NIX_CC/nix-support/dynamic-linker")" \ | ||
--set-rpath | --set-rpath "${libPath}" \ | ||
$out/bin/mybinaryprogram | $out/bin/mybinaryprogram | ||
''; | ''; | ||
}</ | }</syntaxhighlight> | ||
This can be built with: | This can be built with: | ||
< | <syntaxhighlight lang="bash">nix-build mybinaryprogram.nix</syntaxhighlight> | ||
And run with: | And run with: | ||
< | <syntaxhighlight lang="bash">./result/bin/mybinaryprogram</syntaxhighlight> | ||
Another possibility is using a FHS-compatible Sandbox with [https://nixos.org/nixpkgs/manual/#sec-fhs-environments buildFHSUserEnv] | Another possibility is using a FHS-compatible Sandbox with [https://nixos.org/nixpkgs/manual/#sec-fhs-environments buildFHSUserEnv] | ||
< | <syntaxhighlight lang="nix"> | ||
{ pkgs ? import | # fhsUser.nix | ||
{ pkgs ? import <nixpkgs> {} }: | |||
(pkgs.buildFHSUserEnv { | (pkgs.buildFHSUserEnv { | ||
name = | name = "example-env"; | ||
targetPkgs = pkgs: with pkgs; [ | targetPkgs = pkgs: with pkgs; [ | ||
coreutils | coreutils | ||
| Line 166: | Line 180: | ||
mesa_glu | mesa_glu | ||
]; | ]; | ||
runScript = | runScript = "bash"; | ||
}).env</ | }).env</syntaxhighlight> | ||
the sandbox can be entered with | the sandbox can be entered with | ||
< | <syntaxhighlight lang="bash">nix-shell fhsUser.nix</syntaxhighlight> | ||
== What are channels and how they get updated? == | == What are channels and how they get updated? == | ||
[https://github.com/NixOS/nixpkgs Nixpkgs] is the git repository containing all packages and NixOS modules/expressions. Installing packages directly from Nixpkgs master branch is possible but a bit risky as git commits are merged into master before being heavily tested. That's where channels are useful. | [https://github.com/NixOS/nixpkgs Nixpkgs] is the git repository containing all packages and NixOS modules/expressions. Installing packages directly from Nixpkgs master branch is possible but a bit risky as git commits are merged into master before being heavily tested. That's where channels are useful. | ||
A | A "channel" is a name for the latest "verified" git commits in Nixpkgs. Each channel has a different definition of what "verified" means. Each time a new git commit is verified, the channel declaring this verification gets updated. Contrary to an user of the git master branch, a channel user will benefit both from verified commits and binary packages from the binary cache. | ||
Channels are reified as git branches in the [https://github.com/NixOS/nixpkgs-channels nixpkgs-channels repository] and as disk images in the [https://nixos.org/channels/ channels webpage]. There are several channels, each with its own use case and verification phase: | Channels are reified as git branches in the [https://github.com/NixOS/nixpkgs-channels nixpkgs-channels repository] and as disk images in the [https://nixos.org/channels/ channels webpage]. There are several channels, each with its own use case and verification phase: | ||
| Line 211: | Line 225: | ||
If you want to know where <nixpkgs> is located: | If you want to know where <nixpkgs> is located: | ||
< | <syntaxhighlight lang="bash">nix-instantiate --find-file nixpkgs</syntaxhighlight> | ||
To know the commit, open the .version-suffix file in the nixpkgs location. The hash after the dot is the git commit. | To know the commit, open the .version-suffix file in the nixpkgs location. The hash after the dot is the git commit. | ||
| Line 224: | Line 238: | ||
start a new shell with a private mount namespace (Linux-only) | start a new shell with a private mount namespace (Linux-only) | ||
< | <syntaxhighlight lang="bash">sudo unshare -m bash</syntaxhighlight> | ||
remount the filesystem with write privileges (as root) | remount the filesystem with write privileges (as root) | ||
< | <syntaxhighlight lang="bash">mount -o remount,rw /nix/store</syntaxhighlight> | ||
update the file | update the file | ||
< | <syntaxhighlight lang="bash">nano <PATH_TO_PACKAGE>/default.nix</syntaxhighlight> | ||
exit to shell where /nix/store is still mounted read-only | exit to shell where /nix/store is still mounted read-only | ||
< | <syntaxhighlight lang="bash">exit</syntaxhighlight> | ||
Be sure to [https://github.com/NixOS/nixpkgs/issues report the incorrect url] or [https://github.com/NixOS/nixpkgs/pulls fix it yourself]. | Be sure to [https://github.com/NixOS/nixpkgs/issues report the incorrect url] or [https://github.com/NixOS/nixpkgs/pulls fix it yourself]. | ||
| Line 242: | Line 256: | ||
For instance to get the checksum of a git repository use: | For instance to get the checksum of a git repository use: | ||
< | <syntaxhighlight lang="bash">nix-prefetch-git https://git.zx2c4.com/password-store</syntaxhighlight> | ||
== Should I use http://hydra.nixos.org/ as a binary cache? == | == Should I use http://hydra.nixos.org/ as a binary cache? == | ||
| Line 257: | Line 271: | ||
== I'm trying to install NixOS but my Wifi isn't working and I don't have an ethernet port == | == I'm trying to install NixOS but my Wifi isn't working and I don't have an ethernet port == | ||
Most phones will allow you to share your Wifi connection over USB. On Android you can enable this setting via ''Settings'' | Most phones will allow you to share your Wifi connection over USB. On Android you can enable this setting via ''Settings'' > ''Wireless & Networks'' / More ... > ''Tethering & portable hotspot'' > ''USB tethering''. This should be enough to allow you to install NixOS, and then fix your Wifi. iPhones only let you tether using your data connection rather than WiFi. | ||
== How can I disable the binary cache and build everything locally? == | == How can I disable the binary cache and build everything locally? == | ||
Set the binary caches to an empty list: <code>nix.binaryCaches = [];</code> in _configuration.nix or pass ad-hoc <code>--option binary-caches | Set the binary caches to an empty list: <code>nix.binaryCaches = [];</code> in _configuration.nix or pass ad-hoc <code>--option binary-caches ""</code> as parameter to nix-build or its wrappers. | ||
This is also useful to make simple configuration changes in NixOS (ex.: network related), when no network connectivity is available: | This is also useful to make simple configuration changes in NixOS (ex.: network related), when no network connectivity is available: | ||
< | <syntaxhighlight lang="bash">nixos-rebuild switch --option binary-caches ""</syntaxhighlight> | ||
== How do I enable chrooted builds on non-NixOS? == | == How do I enable chrooted builds on non-NixOS? == | ||
Two options have to be added to make chrooted builds work on Nix, ''build-use-chroot'' and ''build-chroot-dirs'': | Two options have to be added to make chrooted builds work on Nix, ''build-use-chroot'' and ''build-chroot-dirs'': | ||
< | <syntaxhighlight lang="nix"> | ||
# /etc/nix/nix.conf | |||
build-use-chroot = true | build-use-chroot = true | ||
build-chroot-dirs = $(nix-store -qR $(nix-build ' | build-chroot-dirs = $(nix-store -qR $(nix-build '<nixpkgs>' -A bash) | xargs echo /bin/sh=$(nix-build '<nixpkgs>' -A bash)/bin/bash) | ||
</syntaxhighlight> | |||
On NixOS set the following in ''configuration.nix'': | On NixOS set the following in ''configuration.nix'': | ||
< | <syntaxhighlight lang="nix"> | ||
nix.extraOptions = '' | |||
build-use-sandbox = true | build-use-sandbox = true | ||
'';</ | ''; | ||
</syntaxhighlight> | |||
== I cannot find $package when running <code>nix-env -qaP</code> even with channels configured == | == I cannot find $package when running <code>nix-env -qaP</code> even with channels configured == | ||
| Line 286: | Line 304: | ||
If you want to install an unfree package as a user, then you need to enable it in ''~/.nixpkgs/config.nix'': | If you want to install an unfree package as a user, then you need to enable it in ''~/.nixpkgs/config.nix'': | ||
< | <syntaxhighlight lang="nix"> | ||
{ | |||
... | ... | ||
allowUnfree = true; | allowUnfree = true; | ||
}</ | } | ||
</syntaxhighlight> | |||
If you want to enable unfree packages system-wide, then set in your <code>/etc/nixos/configuration.nix</code>: | If you want to enable unfree packages system-wide, then set in your <code>/etc/nixos/configuration.nix</code>: | ||
< | <syntaxhighlight lang="nix"> | ||
{ | |||
... | ... | ||
nixpkgs.config.allowUnfree = true; | nixpkgs.config.allowUnfree = true; | ||
}</ | } | ||
</syntaxhighlight> | |||
For temporary allowing unfree packages you can set the environment variable ''NIXPKGS_ALLOW_UNFREE'', e.g. | For temporary allowing unfree packages you can set the environment variable ''NIXPKGS_ALLOW_UNFREE'', e.g. | ||
< | <syntaxhighlight lang="bash">NIXPKGS_ALLOW_UNFREE=1 nix-env</syntaxhighlight> | ||
== How can I install a package from unstable while remaining on the stable channel? == | == How can I install a package from unstable while remaining on the stable channel? == | ||
It is possible to have multiple nix-channels simultaneously. To add the unstable channel with the specifier ''unstable'', | It is possible to have multiple nix-channels simultaneously. To add the unstable channel with the specifier ''unstable'', | ||
< | <syntaxhighlight lang="bash">sudo nix-channel --add https://nixos.org/channels/nixos-unstable unstable</syntaxhighlight> | ||
After updating the channel | After updating the channel | ||
< | <syntaxhighlight lang="bash">sudo nix-channel --update unstable</syntaxhighlight> | ||
queries via <code>nix-env</code> (or <code>nox</code>) will show packages from both ''stable'' and ''unstable''. Use this to install unstable packages into your user environment. The following snippet shows how this can be done in ''configuration.nix''. | queries via <code>nix-env</code> (or <code>nox</code>) will show packages from both ''stable'' and ''unstable''. Use this to install unstable packages into your user environment. The following snippet shows how this can be done in ''configuration.nix''. | ||
< | <syntaxhighlight lang="nix"> | ||
{ config, pkgs, ... }: | |||
let | let | ||
unstable = import | unstable = import <nixos-unstable> {}; | ||
in { | in { | ||
environment.systemPackages = [ unstable.PACKAGE_NAME ]; | environment.systemPackages = [ unstable.PACKAGE_NAME ]; | ||
}</ | } | ||
</syntaxhighlight> | |||
= What is the origin of the name <code>Nix</code> = | = What is the origin of the name <code>Nix</code> = | ||
<blockquote>The name <code>Nix</code> is derived from the Dutch word ''niks'', meaning ''nothing'';build actions do not see anything that has not been explicitly declared as an input | <blockquote>The name <code>Nix</code> is derived from the Dutch word ''niks'', meaning ''nothing'';build actions do not see anything that has not been explicitly declared as an input > [https://pdfs.semanticscholar.org/5fd8/8f89bd8738816e62808a1b7fb12d3ab14a2f.pdf Nix: A Safe and Policy-Free System for Software Deployment, page 2] | ||
</blockquote> | </blockquote> | ||