feat(flake): inputs as GC roots

See NixOS/nix#3995 (comment)
panchoh · Feb 16, 2024 · dea3433 · dea3433
1 parent 0d85363
commit dea3433
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Showing 4 changed files with 29 additions and 1 deletion.
diff --git a/lib/collect-flake-inputs.nix b/lib/collect-flake-inputs.nix
@@ -0,0 +1,10 @@
+flake: let
+  collectFlakeInputs = input:
+    [input]
+    ++ builtins.concatMap collectFlakeInputs (
+      builtins.attrValues (
+        input.inputs or {}
+      )
+    );
+in
+  collectFlakeInputs flake
diff --git a/lib/configurations.nix b/lib/configurations.nix
@@ -8,7 +8,7 @@ builtins.listToAttrs (
       specialArgs =
         inputs
         // {
-          inherit (inputs.self.lib) hmModule;
+          inherit (inputs.self.lib) flakeInputsClosure hmModule;
           inherit box;
         };
     };

diff --git a/lib/default.nix b/lib/default.nix
@@ -1,4 +1,6 @@
 inputs: {
+  flakeInputsClosure = import ./collect-flake-inputs.nix inputs.self;
+
   boxen = import ./boxen.nix inputs;
 
   fmt-alejandra = import ./fmt-alejandra.nix inputs;

diff --git a/modules/traits/flake-sources/default.nix b/modules/traits/flake-sources/default.nix
@@ -0,0 +1,16 @@
+{
+  config,
+  lib,
+  flakeInputsClosure,
+  ...
+}: let
+  cfg = config.traits.flake-sources;
+in {
+  options.traits.flake-sources = {
+    enable = lib.mkEnableOption "flake inputs as GC roots (recursively)" // {default = true;};
+  };
+
+  config = lib.mkIf cfg.enable {
+    system.extraDependencies = flakeInputsClosure;
+  };
+}