DEPRECATION WARNING: @picture will no longer be implicitly assigned to picture. (called from tag at /usr/path/actionpack-2.3.5/lib/action_view/helpers/active_record_helper.rb:250)
Fix is easy - just use @picture not picture. In future Rails versions you will always need to add "@".
Template part with code raising this warning:
<div class="form_row picture"> <% fields_for "pictures", @picture do |picture_form| %> <label><%= t('attribute.description') %>:</label> <%= picture_form.text_field :description %> <%= picture_form.file_field :picture %> <% end %> </div>