buildworld fails with bhyverun.c:1270:6 unused variable???

I have this for some time, had no time to look into this, but 
today I deleted /usr/src, fetched source again, switched to 
stable/13, did a su -l root, removed /etc/make.conf and rebuild, 
same error.

Searching through this list I found nothing. So… I really have no 
idea where to look???

bhyverun.o is build like this:
--- bhyverun.o ---
cc -target x86_64-unknown-freebsd13.1 
--sysroot=/usr/obj/usr/src/amd64.amd64/tmp 
-B/usr/obj/usr/src/amd64.amd64/tmp/usr/bin  -O2 -
pipe -fno-common -march=native 
-I/usr/src/usr.sbin/bhyve/../../contrib/lib9p -I/usr/src/sys 
-DINET -DINET6 -DNETGRAPH -I/usr/src/
sys/dev/e1000 -I/usr/src/sys/dev/mii 
-I/usr/src/sys/dev/usb/controller 
-I/usr/src/contrib/libucl/include -DWITHOUT_CAPSICUM -DBHYV
E_SNAPSHOT -fPIE -g -MD  -MF.depend.bhyverun.o -MTbhyverun.o 
-std=gnu99 -Wno-format-zero-length -fstack-protector-strong 
-Wsystem-
headers -Werror -Wall -Wno-format-y2k -Wno-uninitialized 
-Wno-pointer-sign -Wno-empty-body -Wno-string-plus-int 
-Wno-unused-const-
variable -Wno-error=unused-but-set-variable 
-Wno-tautological-compare -Wno-unused-value 
-Wno-parentheses-equality -Wno-unused-func
tion -Wno-enum-conversion -Wno-unused-local-typedef 
-Wno-address-of-packed-member -Wno-switch -Wno-switch-enum 
-Wno-knr-promoted-p
arameter  -Qunused-arguments    -c 
/usr/src/usr.sbin/bhyve/bhyverun.c -o bhyverun.o

Error looks like this:
--- all_subdir_usr.sbin/bhyve ---
/usr/src/usr.sbin/bhyve/bhyverun.c:1270:6: error: unused variable 
'vcpu' [-Werror,-Wunused-variable]
        int vcpu;
            ^
1 error generated.
*** [bhyverun.o] Error code 1

make[4]: stopped in /usr/src/usr.sbin/bhyve
--- all_subdir_secure ---

make[2]: stopped in /usr/src
--- all_subdir_usr.sbin ---

make[2]: stopped in /usr/src
--- all_subdir_tests ---

make[3]: stopped in /usr/src/tests

make[2]: stopped in /usr/src
--- all_subdir_usr.bin ---

make[2]: stopped in /usr/src
--- all_subdir_lib ---

make[3]: stopped in /usr/src/lib

make[2]: stopped in /usr/src

make[1]: stopped in /usr/src

make: stopped in /usr/src


Any tips or hints where to look welcome!

Cheers,

Mathias

P.S. Will now build without -j 8 over night.

P.P.S.
$ git remote -v
origin  https://git.freebsd.org/src.git (fetch)
origin  https://git.freebsd.org/src.git (push)
$ git status
On branch stable/13
Your branch is up to date with 'origin/stable/13'.

nothing to commit, working tree clean
$ git rev-parse HEAD
4a8af507ebe5cabe87928e36d6f203756903df90


-- 
Mathias Picker                        
Geschäftsführer
Mathias.Picker@virtual-earth.de

virtual earth Gesellschaft für Wissens re/prä sentation mbH
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