Eager Load fails in decidim templates

decidim-admin/config/routes.rb

@@ -39,7 +39,7 @@
       mount manifest.admin_engine, at: "/#{manifest.name}", as: "decidim_admin_#{manifest.name}"
     end
 
-    mount Decidim::Templates::AdminEngine, at: "/templates", as: "decidim_admin_templates" if Decidim.module_installed?(:templates)
+    mount Decidim::Templates::AdminEngine, at: "/templates", as: "decidim_admin_templates"
 
     resources :users, except: [:edit, :update], controller: "users" do
       member do

decidim-core/lib/decidim/core.rb

@@ -870,9 +870,12 @@ def self.module_installed?(mod)
     # user lists e.g. "decidim-core" and "decidim-budgets" in it. In this
     # situation, "decidim-comments" is also needed because it is a dependency
     # for "decidim-budgets".
-    require "decidim/#{mod}"
-
-    true
+    if mod.to_sym == :templates
+      Bundler.definition.dependencies.find { |d| d.name == "decidim-templates" }.present? && require("decidim/#{mod}")
+    else
+      require "decidim/#{mod}"
+      true
+    end
   rescue LoadError
     false
   end

decidim-forms/lib/decidim/forms.rb

@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require "decidim/templates" if Decidim.module_installed?(:templates)
+
 require "decidim/forms/admin"
 require "decidim/forms/api"
 require "decidim/forms/engine"

decidim-surveys/lib/decidim/surveys.rb

@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require "decidim/templates" if Decidim.module_installed?(:templates)
+
 require "decidim/surveys/admin"
 require "decidim/surveys/api"
 require "decidim/surveys/engine"

decidim-templates/lib/decidim/templates/admin_engine.rb

@@ -4,7 +4,7 @@
 
 module Decidim
   module Templates
-    # This is the engine that runs on the public interface of `Templates`.
+    # This is the engine that runs on the admin panel interface of `Templates`.
     class AdminEngine < ::Rails::Engine
       isolate_namespace Decidim::Templates::Admin