我试图在Redmine中安装redmine_mylyn_connector-stable-2.8.zip插件。当我尝试执行Rake命令时，它显示以下错误。有人可以帮忙吗？
bash-4.1# rake redmine:plugins:migrate RAILS_ENV=production
(in /data/redmine/apps/redmine/htdocs)
Could not find gem 'libxml-ruby (>= 2.3.2) ruby' in the gems available on this machine.
Run `bundle install` to install missing gems.
我已经构建了gemfile但它仍然显示相同的错误。