How to skip bundle updates when doing migration?

When I t开发者_如何转开发ried to create a new migration for db, the newest code forced me to do 'bundle install', but because of some network problem I cannot update the gems. Is there an option for migration I can skip updating bundles?

jimmy-mac:new_app jimmy$ rails g migration remove_title_from_offer

Could not find webrat-0.7.3 in any of the sources
Try running `bundle install`.

bundle exec rails g migration remove_title_from_offer

perhaps? Or you could just create a new migration by hand...