From a3c9221d642da4c0b22b9c9576bd2af8dcbb8263 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E2=80=AErekc=C3=A4H=20nitraM=E2=80=AE?=
 <spamfaenger@gmx.de>
Date: Sun, 6 Apr 2025 18:36:51 +0200
Subject: [PATCH] nixos/misc/nixpkgs: add setting
 nixpkgs.config.allowUnfreePackages = ["list" "of "packages"]

Inspired by https://github.com/NixOS/nixpkgs/issues/197325 this adds a
new option nixpkgs.allowUnfreePackages, which merges additively and can
thus be defined in multiple modules close to where the unfree package is
installed.

I would have liked ot name this option
nixpkgs.config.allowUnfreePackages, to define it closer to where the
allowUnfree and allowUnfreePredicate are defined, but I didn't see how
this could be achived. I would welcome some guidance on how to do this.
---
 nixos/modules/misc/nixpkgs.nix     |  3 +++
 pkgs/stdenv/generic/check-meta.nix |  5 ++++-
 pkgs/top-level/config.nix          | 17 +++++++++++++++++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/nixos/modules/misc/nixpkgs.nix b/nixos/modules/misc/nixpkgs.nix
index 449a08a97b61..e832cfd2ebdd 100644
--- a/nixos/modules/misc/nixpkgs.nix
+++ b/nixos/modules/misc/nixpkgs.nix
@@ -20,6 +20,9 @@ let
       rhs = optCall rhs_ { inherit pkgs; };
     in
     lib.recursiveUpdate lhs rhs
+    // lib.optionalAttrs (lhs ? allowUnfreePackages) {
+      allowUnfreePackages = lhs.allowUnfreePackages ++ (lib.attrByPath [ "allowUnfreePackages" ] [ ] rhs);
+    }
     // lib.optionalAttrs (lhs ? packageOverrides) {
       packageOverrides =
         pkgs:
diff --git a/pkgs/stdenv/generic/check-meta.nix b/pkgs/stdenv/generic/check-meta.nix
index 28de9c68110e..688429685863 100644
--- a/pkgs/stdenv/generic/check-meta.nix
+++ b/pkgs/stdenv/generic/check-meta.nix
@@ -158,7 +158,10 @@ let
   #   allowUnfree = false;
   #   allowUnfreePredicate = (x: pkgs.lib.hasPrefix "vscode" x.name);
   # }
-  allowUnfreePredicate = config.allowUnfreePredicate or (x: false);
+  # Defaults to allow all names defined in config.allowUnfreePackages
+  allowUnfreePredicate =
+    config.allowUnfreePredicate
+      or (pkg: builtins.elem (lib.getName pkg) config.allowUnfreePackages or [ ]);
 
   # Check whether unfree packages are allowed and if not, whether the
   # package has an unfree license and is not explicitly allowed by the
diff --git a/pkgs/top-level/config.nix b/pkgs/top-level/config.nix
index c8e8a3f58590..9d8f1e442c5a 100644
--- a/pkgs/top-level/config.nix
+++ b/pkgs/top-level/config.nix
@@ -226,6 +226,23 @@ let
       '';
     };
 
+    allowUnfreePackages = mkOption {
+      type = with lib.types; listOf str;
+      default = [ ];
+      example = [ "ut1999" ];
+      description = ''
+        Allows specific unfree packages to be used.
+
+        This option composes with `nixpkgs.config.allowUnfreePredicate` by also allowing the listed package names.
+
+        Unlike `nixpkgs.config.allowUnfreePredicate`, this option merges additively, similar to `environment.systemPackages`.
+        This enables defining allowed unfree packages in multiple modules, close to where they are used.
+
+        This avoids the need to centralize all unfree package declarations or globally enable unfree packages via
+        `nixpkgs.config.allowUnfree = true`.
+      '';
+    };
+
     allowBroken = mkOption {
       type = types.bool;
       default = false;