Yesterday evening during the process of building a new release of Chef the chef gem was pushed to RubyGems ahead of the complete omnibus release making it out to OmniTruck. Unfortunately, this has broken vagrant-omnibus for anyone that has the version set to latest or hasn’t explicitly set a version. We are sorry about this and are working to get a fix out quickly.
Because pulling a gem creates a different set of problems, we have decided to leave the gem up, as it is. We are working to get the release this is tied to out as quickly as possible, but, in the meantime, specifying version 11.16.0, instead of latest, will work around this issue. We are sorry for the trouble this has caused.
Additionally, a pull request has been opened against the vagrant-omnibus project to correct the underlying issue going forward.
Thank you for your patience as we work through this issue.