correctifs

app/controllers/admin/education/application_controller.rb

 class Admin::Education::ApplicationController < Admin::ApplicationController
   def breadcrumb
-    super
-    add_breadcrumb Education.model_name.human
+    if @program
+      short_breadcrumb
+    else
+      super
+      add_breadcrumb Education.model_name.human
+    end
+
   end
 end

app/controllers/admin/education/programs_controller.rb

@@ -30,7 +30,6 @@ class Admin::Education::ProgramsController < Admin::Education::ApplicationContro
   end
 
   def update
-    byebug
     if @program.update(program_params)
       redirect_to [:admin, @program], notice: t('admin.successfully_updated_html', model: @program.to_s)
     else

app/models/concerns/with_slug.rb

@@ -4,6 +4,7 @@ module WithSlug
   included do
     validates :slug,
               uniqueness: { scope: :university_id },
-              format: { with: /\A[a-z0-9\-]+\z/, message: "ne peut contenir que des lettres minuscules, des chiffres et des traits d'union." }
+              format: { with: /\A[a-z0-9\-]+\z/, message: "ne peut contenir que des lettres minuscules, des chiffres et des traits d'union." },
+              allow_blank: true
   end
 end