i try to install: http://www.redmine.org/plugins/redmine_better_gantt_chart. first i installed "gem install redmine_plugin_support". but on running "rake db:migrate:plugins RAILS_ENV=production" i get: "Don't know how to build task 'db:migrate:plugins'"
can't install plugin: "Don't know how to build task 'db:migrate_plugins'" (better gantt chart plugin)