Where "long way round" means "update your system using apt update && apt full-upgrade".Be careful if you are using ZFS on your RPi.
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Welp, looks like the 6.12 kernel is not support yet for ZFS. Going to have to sit on my hands for a bit until that is sorted out.
[EDIT]
Turns out, you just need to go the long way around.
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Raspberry Pi OS has been on kernel 6.12 for some time now - it looks like you've not updated your system for a while, and have then tried to install the new RT kernel package without updating the rest of the system. Raspberry Pi actually provide their own version of the zfs-dkms package, which seems to be just a copy of the version from bookworm-backports with ~rpt1 tacked onto the version number. Handily, you don't have the enable bookworm-backports to get it:
Code:
andrew@pi5bookworm:~ $ apt policy zfs-dkmszfs-dkms: Installed: (none) Candidate: 2.3.1-1~bpo12+1~rpt1 Version table: 2.3.1-1~bpo12+1~rpt1 500 500 http://archive.raspberrypi.com/debian bookworm/main arm64 Packages 500 http://archive.raspberrypi.com/debian bookworm/main armhf Packages 2.1.11-1+deb12u1 500 500 http://deb.debian.org/debian bookworm/contrib arm64 Packages 500 http://deb.debian.org/debian bookworm/contrib armhf PackagesStatistics: Posted by andrum99 — Thu Jul 17, 2025 8:17 am