Repository settings changed
The Linuxcnc installer sets up your repositories. This appears broken. I think the issue is the key has expired Our relevant files are https://github.com/LinuxCNC/linuxcnc-live-build/blob/cdd0406a7feac2d1de61ab444d117e564de9e706/config/hooks/normal/500-install-ethercat--key.hook.chroot
Bjarne helped me set this up previously. Your help to resolve this would be appreciated again.