https://vlc-bluray.whoknowsmy.name/

Did not try but the library tyeg are mentioned ia in Debian and Ubuntu repos so you only need to download there the keysdb.

Installing libblueray2 library would also install libaacs0 library for this in Debian.

If it does not work: either the KEYSDB is outdated or the encryption of your blue ray is BD+ (libbdplus), which requires other library and other set of keys.

I gave in and bought makemkv yesterday. It just works.

you might want to have a look at this software: https://github.com/beandog/bluray_info makemkv is not libre software.

I just used Handbrake, but there has been one or two discs that it couldn't see, presumably due to some overly aggressive protection.

I haven't run into any issues with MakeMKV, which I bought years ago. Only issue I ran into was some UHD discs won't read properly, but that was an issue with my Blu-Ray device. I have a new-ish Pioneer with a firmware flash and it reads everything fine.

mkvtoolnix is pretty good. It doesn't catch special features and other extras from the disk, but getting the main movie is usually not an issue.

I ripped 298 Blu-Rays and a smaller number of DVDs with MakeMKV. Twice because I lost the whole collection due to my own bs the first time (make sure you have excellent backups, folks). I would not go through the process a third time, but that has nothing to do with the software.

would cdrdao or dd work? They're pretty robust... rip it and see if it plays