Flakes: Difference between revisions

Line 1:

Nix ~~flakes is some~~ upcoming feature in the Nix package manager.

'''Nix Flakes''' are an upcoming feature of the Nix package manager.

~~It allows to download nix expressions from other sources~~

~~in a declarative way by specifying them a flake.nix file.~~

~~Those sources are called flakes and also have a flake.nix~~

~~where they can describe their own dependencies.~~

~~Sources can be tarballs, git, local directories or mercurial repositories.~~

~~It makes evaluation reproducible with providing a lock called flake.lock.~~

~~This lock file provides hashes for sources and locks the revision~~

~~of external version control system.~~

~~Nix flakes intents to replace nix channels and the nix search path (<code>NIX_PATH</code>)~~.

== Installing ~~nix~~ flakes ==

Flakes allow you to specify your code's dependencies (e.g. remote Git repositories) in a declarative way, simply by listing them inside a <code>flake.nix</code> file:

{

inputs = {

home-manager.url = "github:rycee/home-manager";

};

}

</syntaxHighlight>

Each dependency gets then pinned, that is: its commit hash gets automatically stored into a file - named <code>flake.lock</code> - making it easy to, say, upgrade it:

$ nix flake update --update-input home-manager

</syntaxHighlight>

''(if you're familiar with modern packages managers like <code>cargo</code> or <code>npm</code>, then the overall mechanism shouldn't surprise you - Nix works in a similar way, although without a centralized repository.)''

Flakes are meant as a replacement for '''channels''' and things like ad-hoc invocations of <code>builtins.fetchgit</code> - no more worrying about keeping your channels in sync, no more worrying about forgetting about a dependency deep down in your tree: everything's at hand inside <code>flake.lock</code>.

== Installing flakes ==

Currently flakes are available only in the '''unstable''' version of Nix and so they need to be explicitly enabled inside '''nix.conf'''.

~~Right now nix flakes are only available in the unstable nix version and need to be enabled in nix.conf as well.~~

=== NixOS ===

In NixOS this can be achieved with the following line in <code>configuration.nix</code>

Line 28:

Line 40:

=== Non-NixOS ===

On non-nixos ~~system~~ install `nixUnstable` in your environment:

On non-nixos systems, install `nixUnstable` in your environment:

@@ Line 1: / Line 1: @@
-Nix flakes is some upcoming feature in the Nix package manager.
+'''Nix Flakes''' are an upcoming feature of the Nix package manager.
-It allows to download nix expressions from other sources
-in a declarative way by specifying them a flake.nix file.
-Those sources are called flakes and also have a flake.nix
-where they can describe their own dependencies.
-Sources can be tarballs, git, local directories or mercurial repositories.
-It makes evaluation reproducible with providing a lock called flake.lock.
-This lock file provides hashes for sources and locks the revision
-of external version control system.
-Nix flakes intents to replace nix channels and the nix search path (<code>NIX_PATH</code>).
-== Installing nix flakes ==
+Flakes allow you to specify your code's dependencies (e.g. remote Git repositories) in a declarative way, simply by listing them inside a <code>flake.nix</code> file:
+<syntaxHighlight lang=nix>
+{
+  inputs = {
+    home-manager.url = "github:rycee/home-manager";
+  };
+}
+</syntaxHighlight>
+Each dependency gets then pinned, that is: its commit hash gets automatically stored into a file - named <code>flake.lock</code> - making it easy to, say, upgrade it:
+<syntaxHighlight lang=console>
+$ nix flake update --update-input home-manager
+</syntaxHighlight>
+''(if you're familiar with modern packages managers like <code>cargo</code> or <code>npm</code>, then the overall mechanism shouldn't surprise you - Nix works in a similar way, although without a centralized repository.)''
+Flakes are meant as a replacement for '''channels''' and things like ad-hoc invocations of <code>builtins.fetchgit</code> - no more worrying about keeping your channels in sync, no more worrying about forgetting about a dependency deep down in your tree: everything's at hand inside <code>flake.lock</code>.
+== Installing flakes ==
+Currently flakes are available only in the '''unstable''' version of Nix and so they need to be explicitly enabled inside '''nix.conf'''.
-Right now nix flakes are only available in the unstable nix version and need to be enabled in nix.conf as well.
 === NixOS ===
 In NixOS this can be achieved with the following line in <code>configuration.nix</code>
@@ Line 28: / Line 40: @@
 === Non-NixOS ===
-On non-nixos system install `nixUnstable` in your environment:
+On non-nixos systems, install `nixUnstable` in your environment:
 <syntaxHighlight lang=console>