# pcf_dos build on guest (DragonFly cc 8.3):
$ cc -O -Wall -o pcf_dos pcf_dos.c
BUILD_OK (no warnings, exit 0)

# Kernel builds (baseline PCFTEST #0 and fixed PCFTEST #1), from build logs
# (guest /tmp is tmpfs; completion lines captured at build time):
>>> Kernel build for PCFTEST completed on Sat Sep 26 05:33:29 UTC 2026  [baseline, unmodified pcfclock.c]
>>> Kernel install for PCFTEST completed on Sat Sep 26 05:35:40 UTC 2026
>>> Kernel install for PCFTEST completed on Sat Sep 26 05:48:46 UTC 2026  [fix.diff applied to /usr/src/sys/dev/misc/pcfclock/pcfclock.c]

# guest source md5 after fix: bdd7e2d88ac81176b41445a9d9147051 (== intended fixed file)