Note that if you are using the nginx.org repository or the PPAs that *all third party repositories are disabled* when you run a `do-release-upgrade`, so third-party-repository-specific things will never be seen, which can lead to the errors you're seeing here.
Note that if you are using the nginx.org repository or the PPAs that *all third party repositories are disabled* when you run a `do-release- upgrade` , so third-party- repository- specific things will never be seen, which can lead to the errors you're seeing here.