Package: kalgebra Version: 4:20.12.1-1 Followup-For: Bug #1016658 There is a dependency chain which leads to sse2-support. And in the near future it will be sse3-support. kalgebra needs libqt5webenginewidgets5 which needs libqt5webenginecore5 which needs sse2-support, but only since bookworm, they have forget to add it in bullseye, see related bug here: https://bugs.debian.org/1003249