Bug#940028: debian-installer multi-console race with preseeding
Ian Jackson writes ("debian-installer multi-console race with preseeding"):
> A workaround is to specify *exactly one* appropriate console=
> on the kernel command line. This causes the kernel to report only
> that console in /proc/consoles and the bug is avoided.
This seems to work only sometimes. In my experience it worked for an
arm64 server but not for an x86 PV Xen guest. There does not appear
to be another workaround that does not involve modifying the installer