Flakes: Difference between revisions

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When output <code>apps.<system>.myapp</code> is not defined, <code>nix run myapp</code> runs <code><packages or legacyPackages.<system>.myapp>/bin/<myapp.meta.mainProgram or myapp.pname or myapp.name (the non-version part)></code>

== Using flakes ~~project from a legacy~~ Nix ==

== Using flakes with stable Nix ==

If you want to use a flake from a 'regular' derivation on a system that does have flakes enabled, you can use something like <code>(builtins.getFlake "path:/path/to/directory").packages.x86_64-linux.default</code>, where 'directory' is the ~~directory that contains your <code>flake.nix</code>.~~

There exists the [https://github.com/edolstra/flake-compat flake-compat] library that you can use to shim <code>default.nix</code> and <code>shell.nix</code> files. It will download the inputs of the flake, pass them to the flake’s <code>outputs</code> function and return an attribute set containing <code>defaultNix</code> and <code>shellNix</code> attributes. The attributes will contain the output attribute set with an extra <code>default</code> attribute pointing to current platform’s <code>defaultPackage</code> (resp. <code>devShell</code> for <code>shellNix</code>).

~~There is also a~~ [https://github.com/edolstra/flake-compat flake-compat] library you can use to shim ~~legacy~~ <code>default.nix</code> and <code>shell.nix</code> files. It will download the inputs of the flake, pass them to the flake’s <code>outputs</code> function and return an attribute set containing <code>defaultNix</code> and <code>shellNix</code> attributes. The attributes will contain the output attribute set with an extra <code>default</code> attribute pointing to current platform’s <code>defaultPackage</code> (resp. <code>devShell</code> for <code>shellNix</code>).

Place the following into <code>default.nix</code> (for <code>shell.nix</code>, replace <code>defaultNix</code> with <code>shellNix</code>) to use the shim:

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}).defaultNix

</syntaxHighlight>

== Accessing flakes from Nix expressions ==

If you want to access a flake from within a regular Nix expression on a system that has flakes enabled, you can use something like <code>(builtins.getFlake "path:/path/to/directory").packages.x86_64-linux.default</code>, where 'directory' is the directory that contains your <code>flake.nix</code>.

== Making your evaluations pure ==

@@ Line 173: / Line 173: @@
 When output <code>apps.<system>.myapp</code> is not defined, <code>nix run myapp</code> runs <code><packages or legacyPackages.<system>.myapp>/bin/<myapp.meta.mainProgram or myapp.pname or myapp.name (the non-version part)></code>
-== Using flakes project from a legacy Nix ==
+== Using flakes with stable Nix ==
-If you want to use a flake from a 'regular' derivation on a system that does have flakes enabled, you can use something like <code>(builtins.getFlake "path:/path/to/directory").packages.x86_64-linux.default</code>, where 'directory' is the directory that contains your <code>flake.nix</code>.
+There exists the [https://github.com/edolstra/flake-compat flake-compat] library that you can use to shim <code>default.nix</code> and <code>shell.nix</code> files. It will download the inputs of the flake, pass them to the flake’s <code>outputs</code> function and return an attribute set containing <code>defaultNix</code> and <code>shellNix</code> attributes. The attributes will contain the output attribute set with an extra <code>default</code> attribute pointing to current platform’s <code>defaultPackage</code> (resp. <code>devShell</code> for <code>shellNix</code>).
-There is also a [https://github.com/edolstra/flake-compat flake-compat] library you can use to shim legacy <code>default.nix</code> and <code>shell.nix</code> files. It will download the inputs of the flake, pass them to the flake’s <code>outputs</code> function and return an attribute set containing <code>defaultNix</code> and <code>shellNix</code> attributes. The attributes will contain the output attribute set with an extra <code>default</code> attribute pointing to current platform’s <code>defaultPackage</code> (resp. <code>devShell</code> for <code>shellNix</code>).
 Place the following into <code>default.nix</code> (for <code>shell.nix</code>, replace <code>defaultNix</code> with <code>shellNix</code>) to use the shim:
@@ Line 213: / Line 211: @@
 }).defaultNix
 </syntaxHighlight>
+== Accessing flakes from Nix expressions ==
+If you want to access a flake from within a regular Nix expression on a system that has flakes enabled, you can use something like <code>(builtins.getFlake "path:/path/to/directory").packages.x86_64-linux.default</code>, where 'directory' is the directory that contains your <code>flake.nix</code>.
 == Making your evaluations pure ==