FIX-KERNEL BUILD LOG (patched kbdsw.c via fix.diff, nativekernel path)
=======================================================================
(The in-guest /tmp/build.log was wiped by the validation reboot; this file
records the exact commands and their captured output from this session.)

$ cd /usr/src && patch -p1 --dry-run < /tmp/fix.diff && patch -p1 < /tmp/fix.diff
done
PATCHED

$ cd /usr/src && make -j6 buildkernel KERNCONF=X86_64_GENERIC   # first attempt
rc=2
You must buildworld before buildkernel. ... use the nativekernel target

$ cd /usr/src && make -j6 nativekernel KERNCONF=X86_64_GENERIC
rc=0
>>> Kernel build for X86_64_GENERIC completed on Fri Oct  2 18:49:47 UTC 2026

$ cd /usr/src && make installkernel KERNCONF=X86_64_GENERIC
rc=0
>>> Kernel install for X86_64_GENERIC completed on Fri Oct  2 18:50:58 UTC 2026

$ shutdown -r now
-> rebooted into the patched kernel:
DragonFly 6.5-DEVELOPMENT #1: Fri Oct  2 18:46:22 UTC 2026
    root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC

PATCHED-KERNEL RACE RESULT (same PoC workload as baseline):
- ~150+ device_del/device_add cycles with 6-thread console-ioctl spam,
  syscons rebound to ukbd0 each cycle; guest stayed UP, no panic
  (see run.2.log / session logs).