dpkg -s kdegraphics-thumbnailers tells me:
----------------------------------------cut here ---------------------------------------
Package: kdegraphics-thumbnailers
Status: install ok installed
Priority: optional
Section: kde
Installed-Size: 168
Maintainer: Debian Qt/KDE Maintainers <debian-qt-kde@lists.debian.org>
Architecture: amd64
Version: 4:22.12.0-1
-----------------------------------------------
Replaces: kdegraphics-mobipocket (<< 4:21.12.3)
-----------------------------------------------
Depends: kio, libc6 (>= 2.15), libkf5archive5 (>= 5.90.0~), libkf5kdcraw5 (>= 4.12.3), libkf5kexiv2-15.0.0 (>= 4.5.90), libkf5kiowidgets5 (>= 5.90.0~), libqmobipocket2 (>= 4:16.12.0), libqt5core5a (>= 5.15.2~), libqt5gui5 (
>= 5.15.2~) | libqt5gui5-gles (>= 5.15.2~), libstdc++6 (>= 5)
Recommends: ghostscript
Breaks: kdegraphics-mobipocket (<< 4:21.12.3)
Description: graphics file format thumbnailers for KDE SC
These plugins allow KDE software to create thumbnails for several
advanced graphic file formats (PS, RAW).
.
This package is part of the KDE graphics module.
Homepage:
https://invent.kde.org/graphics/kdegraphics-thumbnailers --------------------------------- cut here ----------------------------------------
And as far as I can tell kdegraphics-mobipocket is no longer part of Debian sid.
The latest version 4:21.12.3-1 from bookworm (testing) is not compatible
with the current sid version 4:22.12.0-2 of
libqmobipocket.