First of all, thank you very much for maintaining apt. It seems to me that Debian's fine system administration tools, like apt, make the life of system administrators easier.
The main reason I'm writing is I may have replicated the bug originally reported here. In 2019. While trying to upgrade a computer running stable to testing on DVDs. Here's what I tried: root$ cd-rom add # With testing DVD 1 in the optical drive root$ cd-rom add # With testing DVD 2 in the optical drive root$ cd-rom add # With testing DVD 3 in the optical drive root$ apt update Ign:1 cdrom://[Debian GNU/Linux testing _Bullseye_ - Official Snapshot i386 DVD Binary-1 (date and time bla bla bla)] bullseye InRelease (5 similar error messages) Err:7 cdrom://[Debian GNU/Linux testing _Bullseye_ - Official Snapshot i386 DVD Binary-1 (date and time bla bla bla)] bullseye Release Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs (10 similar error messages) Reading package lists... Done E: The repository 'cdrom://[Debian GNU/Linux testing _Bullseye_ - Official Snapshot i386 DVD Binary-1 (date and time bla bla bla)] Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. (10 similar error messages) N: See apt-secure(8) manpage for repository creation and user configuration details. I also tried root$ apt-get update and editing /etc/apt/sources.list by commenting out stable's cdrom lines and inserting between the words "deb" and "cdrom:" [ trusted=yes ] and [ trusted=yes allow-insecure=yes ] No luck. So, Kingsley -- Time is the fire in which we all burn.