rake db上的错误:用杂种迁移，“找不到杂种”

I am trying to install track, a ruby on rails application on ubuntu 10.04. Bundle install works fine, however when I run rake db:migrate I get some deprecation warnings, and then an error claiming that system "Could not find mongrel" despite the fact that it is installed. If I list the gems mongrel is clearly on the list, but when running rake commands I get this error. Any ideas?I am trying to install track, a ruby on rails a