mailnag: implement a withPlugins interface

pkgs/applications/networking/mailreaders/mailnag/default.nix

@@ -15,20 +15,14 @@
 , gobject-introspection
 # Available plugins (can be overriden)
 , availablePlugins
-# Plugins to install
-, plugins ? [ "goa" ]
+# Used in the withPlugins interface at passthru, can be overrided directly, or
+# prefarably via e.g: `mailnag.withPlugins(["goa"])`
+, mailnag
+, userPlugins ? [ ]
+, pluginsDeps ? [ ]
 }:
 
-let
-  # Get the list of plugins the user wants
-  userPlugins = lib.attrVals plugins availablePlugins;
-  # goa plugin requires gio's gnome-online-accounts which requires making sure
-  # mailnag runs with GI_TYPELIB_PATH containing the path to Goa-1.0.typelib.
-  # This is handled best by adding the plugins' deps to buildInputs and let
-  # wrapGAppsHook handle that.
-  pluginsDeps = lib.flatten (lib.catAttrs "buildInputs" userPlugins);
-in
-  python3Packages.buildPythonApplication rec {
+python3Packages.buildPythonApplication rec {
   pname = "mailnag";
   version = "2.0.0";
 
@@ -68,6 +62,17 @@ in
 
   passthru = {
     inherit availablePlugins;
+    withPlugins =
+      plugs:
+      let
+        # goa plugin requires gio's gnome-online-accounts which requires making sure
+        # mailnag runs with GI_TYPELIB_PATH containing the path to Goa-1.0.typelib.
+        # This is handled best by adding the plugins' deps to buildInputs and let
+        # wrapGAppsHook handle that.
+        pluginsDeps = lib.flatten (lib.catAttrs "buildInputs" plugs);
+        self = mailnag;
+      in
+        self.override { userPlugins = plugs; };
   };
 
   # See https://nixos.org/nixpkgs/manual/#ssec-gnome-common-issues-double-wrapped
@@ -97,4 +102,4 @@ in
     platforms = platforms.linux;
     maintainers = with maintainers; [ doronbehar ];
   };
-  }
+}

pkgs/top-level/all-packages.nix

@@ -5213,6 +5213,9 @@ in
       goa = callPackage ../applications/networking/mailreaders/mailnag/goa-plugin.nix { };
     };
   };
+  mailnagWithPlugins = mailnag.withPlugins(
+    builtins.attrValues mailnag.availablePlugins
+  );
 
   mailsend = callPackage ../tools/networking/mailsend { };