It seems that it comes from the removal of the repository jessie-updates by debian (see this current discussion https://www.mail-archive.com/debian-user@lists.debian.org/msg740473.html) although I don’t know if it’s intended or an error.
As a temporary solution, I removed the line deb http://deb.debian.org/debian/ jessie-updates main from the /etc/apt/sources.list of the docker image in which the CI process runs, by putting this in my .gitlab-ci.yml
before_script:
- echo -e "deb http://deb.debian.org/debian jessie main\ndeb http://security.debian.org jessie/updates main" > /etc/apt/sources.list
This is only to get my CI running today, but I hope this will resolved either by the debian team (fixing their repository), or by the docker image maintainer to adjust to these changes