nix-plugins

A collection of useful Nix native plugins.

extra-builtins

This plugin adds a setting extra-builtins-file and two builtins:

• builtins.extraBuiltins: If the extra-builtins-file exists, it is imported and passed a set containing at least the importNative and exec primops, even if allow-unsafe-native-code-during-evaluation is false, and the result is available as extraBuiltins. If the file does not exist, extraBuiltins will be null.
• builtins.nix-cflags: A set of required flags needed to build a native plugin against the same version of Nix this plugin is compiled against. See nix-plugins-config.h.in for the list of attributes in the set.

This allows users to specify a fixed set of safe extra builtins without enabling arbitrary Nix expressions to run arbitrary native code. The expectation is that extra-builtins-file defines a set of builtins, but ultimately that's up to the end user.

Install

To enable these plugins system-wide on NixOS, add the following to your configuration:

nix.extraOptions = ''
  plugin-files = ${pkgs.nix-plugins}/lib/nix/plugins
'';