Clean Debian stretch release update impossible due to lookup for jessie back ports
An eternity after stretch upgrade I can’t update it anymore. I’m suddenly getting the error
E: The repository ’http://ftp.debian.org/debian jessie-backports Release’ does no longer have a Release file.
However, my sources-list are configured to stretch:
deb http://ftp.debian.org/debian stretch-backports main
Why is apt update calling for Jessie back ports?