If I use the Typo's generator for sidebar I am an error :

shingara@slick ~/perso/project/typo_trunk $ ./script/generate sidebar TestSidebar
      create  vendor/plugins/test_sidebar/lib
      create  vendor/plugins/test_sidebar/test
      create  vendor/plugins/test_sidebar/views
      create  vendor/plugins/test_sidebar/init.rb
      create  vendor/plugins/test_sidebar/lib/test_sidebar.rb
      create  vendor/plugins/test_sidebar/test/test_sidebar_test.rb
      create  vendor/plugins/test_sidebar/Rakefile
      create  vendor/plugins/test_sidebar/views/content.rhtml
No such file or directory - /home/shingara/perso/project/typo_trunk/lib/generators/sidebar/templates/content.rhtml

So the file vendor/plugins/test_sidebar/views/content.rhtml is empty

This error is made because in lib/generators/sidebar/templates/ there are no file content.rhtml but a content.html.erb So you need change this filename by content.rhtml.

You can't change the name of content.rhtml in sidebar because now the render_sidebar use this particular file and all sidebar use this and not another.

I can made a patch to test if there are a file content.html.erb or content.rhtml before. But I don't know if it's a good idea.