lib: initialize env-specific subset for wrapper-manager-fds

lib/env-specific/wrapper-manager.nix

@@ -0,0 +1,26 @@
+{ pkgs, lib, self }:
+
+{
+  /* Given a Blender package and its addons to be wrapped, create a derivation
+     containing all of the addons properly placed as a system resource folder.
+  */
+  wrapBlenderAddons = { blenderPackage, addons }:
+    let
+      blenderVersion = lib.versions.majorMinor blenderPackage.version;
+    in
+    pkgs.runCommand "blender-system-resources"
+      {
+        passAsFile = [ "paths" ];
+        paths = addons ++ [ blenderPackage ];
+        nativeBuildInputs = with pkgs; [ outils ];
+      } ''
+      mkdir -p $out
+      for i in $(cat $pathsPath); do
+        resourcesPath="$i/share/blender"
+        if [ -d $i/share/blender/${blenderVersion} ]; then
+          resourcesPath="$i/share/blender/${blenderVersion}";
+        fi
+        lndir -silent $resourcesPath $out
+      done
+    '';
+}