Thank you for your bug report. Adding the official Ubuntu repository for security updates is a design decision to ensure that all users get security updates quickly without having to wait for local mirrors to synchronise. However, software-properties should probably add the URL for the local mirror too.
Thank you for your bug report. Adding the official Ubuntu repository for security updates is a design decision to ensure that all users get security updates quickly without having to wait for local mirrors to synchronise. However, software-properties should probably add the URL for the local mirror too.