The bug can be closed. After some investigation it appears that this is some misconfiguration with my installation of BHYVE.
More: https://forums.freebsd.org/threads/bhyve-linux-kernel-4-19-doesnt-boot-but-4-14-does.78789/
- Bug#981851: linux-image-4.19.0-13-amd64: kernel... Leszek
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- Bug#981851: marked as done (linux-image-4.... Debian Bug Tracking System
