Sorry about that. The
final repository for melodic currently contains the the final snapshot for Debian Stretch which is no longer supported.
Snapshots are still manually taken by me when I get the release announcement email so the only reason the recent melodic snapshot was missing is that I got distracted before taking it. I’ve taken the snapshot now so it should be online.
Previously I recommended creating topics in the Buildfarm category to report snapshot issues but we now have an infrastructure repository specifically for fielding infrastructure issue reports GitHub - osrf/infrastructure: Repository for tracking issues across Open Robotics infrastructure and I’d suggest reporting issues there.