There has been some discussion of this bug at the apt-cacher-ultra web site.
https://github.com/linsomniac/apt-cacher-ultra/discussions/9 -- Does anybody read signatures any more? https://charlescurley.com https://charlescurley.com/blog/
- Bug#1150279: auto-apt-proxy does not detect apt-cacher-ultr... root
- Bug#1150279: Discussion at Charles Curley
