After several years, I decided to upgrade my Debian Buster old Dell xps-13 to bookworm. I first made sure that Buster was updated, then switched my sources.list to , bookworm, including a non-free-firmware clause to the list. I noticed on the update phase, using the following list: bookworm stable main contrib non-free non-free-firmware seemed to ignore the "stable" directive. The laptop now refuses to boot. I get the following errors "failed to startOpenBSD secure shell server,failed to start Network Time synchronization failed to start MariaDB failed to start Gnome Display Manager. Short of downloading and installing a newly downloaded version of bookworm, can someone suggest an alternative approach?

Thank you.

Why would you do bookworm stable? Bookworm is still testing, and stable is Bullseye. The way you have it you're saying to go to Bookworm with the component of stable, which doesn't exist. The only components under Bookworm are main contrib non-free non-free-firmware.

Probably need to boot from external media, chroot into your install, fix sources.list to remove either stable or bookworm, then do a full-upgrade to actually get it into being a proper target. Going Buster straight to Bookworm will probably fail though without going Bullseye as an interim step as there's just too much that's changed and I'd expect failures upon attmepting to boot.