Build failure in /usr/src/sys/dev/thunderbolt/tb_pcib.c:307:6

(Sorry if this has already been seen & addressed; I don't have ready
access to email archives just now.)

During an in-plpace source-based update from:

FreeBSD freebeast.catwhisker.org 16.0-CURRENT FreeBSD 16.0-CURRENT #592 main-n286328-ea4888e63f6a: Tue Jun  2 11:29:57 UTC 2026     root@freebeast.catwhisker.org:/common/S4/obj/usr/src/amd64.amd64/sys/GENERIC amd64 1600018 1600018

to main-n286341-309fc9f76591

I see:
...
Building /common/S4/obj/usr/src/amd64.amd64/sys/GENERIC/subr_clockcalib.o
Building /common/S4/obj/usr/src/amd64.amd64/sys/GENERIC/force-dynamic-hack.pico
--- tb_pcib.o ---
/usr/src/sys/dev/thunderbolt/tb_pcib.c:307:6: error: variable 'error' set but not used [-Werror,-Wunused-but-set-variable]
  307 |         int error __diagused;
      |             ^
1 error generated.
*** [tb_pcib.o] Error code 1

make[2]: stopped making "all" in /common/S4/obj/usr/src/amd64.amd64/sys/GENERIC
.ERROR_TARGET='tb_pcib.o'
.ERROR_META_FILE='/common/S4/obj/usr/src/amd64.amd64/sys/GENERIC/tb_pcib.o.meta'
.MAKE.LEVEL='2'
MAKEFILE=''
.MAKE.MODE='meta missing-filemon=yes missing-meta=yes silent=yes verbose curdirOk=yes'
_ERROR_CMD='cc -target x86_64-unknown-freebsd16.0 --sysroot=/common/S4/obj/usr/src/amd64.amd64/tmp -B/common/S4/obj/usr/src/amd64.amd64/tmp/usr/bin -c -O2 -pipe  -fno-strict-aliasing  -g -nostdinc  -I. -I/usr/src/sys -I/usr/src/sys/contrib/ck/include -I/usr/src/sys/contrib/libfdt -D_KERNEL -DHAVE_KERNEL_OPTION_HEADERS -include opt_global.h -fno-common   -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -fdebug-prefix-map=./machine=/usr/src/sys/amd64/include -fdebug-prefix-map=./x86=/usr/src/sys/x86/include -fdebug-prefix-map=./i386=/usr/src/sys/i386/include -mcmodel=kernel -mno-red-zone -mno-mmx -mno-sse -msoft-float  -fno-asynchronous-unwind-tables -ffreestanding -fwrapv -fstack-protector-strong  -gdwarf-4 -Wall -Wstrict-prototypes -Wmissing-prototypes -Wpointer-arith -Wcast-qual -Wundef -Wno-pointer-sign -D__printf__=__freebsd_kprintf__ -Wmissing-include-dirs -fdiagnostics-show-option -Wno-unknown-pragmas -Wswitch -Wno-error=tautological-compare -Wno-error=empty-body -Wno-error=parentheses-equality -Wno-error=unused-function -Wno-error=pointer-sign -Wno-error=shift-negative-value -Wno-address-of-packed-member -Wno-format-zero-length   -mno-aes -mno-avx  -std=gnu17 -Werror /usr/src/sys/dev/thunderbolt/tb_pcib.c; ctfconvert -L VERSION -g tb_pcib.o;'
.CURDIR='/common/S4/obj/usr/src/amd64.amd64/sys/GENERIC'
.MAKE='make'
.OBJDIR='/common/S4/obj/usr/src/amd64.amd64/sys/GENERIC'
.TARGETS='all'
CPUTYPE=''
DESTDIR=''
LD_LIBRARY_PATH=''
MACHINE='amd64'
MACHINE_ARCH='amd64'
MACHINE_CPUARCH='amd64'
MAKEOBJDIRPREFIX=''
....

I will attach the ERROR_META_FILE.

Peace,
david
-- 
David H. Wolfskill                              david@catwhisker.org

See https://www.catwhisker.org/~david/publickey.gpg for my public key.