Kernel build fails for stable

I updated sources and did a buildworld for 13/stable updated about
2021-07-18 22:50. Still trying to figure out how to get the hash. Sorry.

buildkernel dies building /usr/local/sys/modules/drm-fbsd13-kmod/linuxkpi.
Build of linux_compat.o fails with the rather long chain of includes with:
In file included from
/usr/src/sys/compat/linuxkpi/common/include/linux/device.h:36:
In file included from
/usr/local/sys/modules/drm-fbsd13-kmod/linuxkpi/gplv2/include/linux/kobject.h:4:
In file included from
/usr/src/sys/compat/linuxkpi/common/include/linux/kobject.h:37:
/usr/src/sys/compat/linuxkpi/common/include/linux/kref.h:118:2: error:
implicit declaration of function '__stringify' is invalid in C99
[-Werror,-Wimplicit-function-declaration]
        WARN_ON(release == NULL);
        ^
/usr/src/sys/compat/linuxkpi/common/include/linux/kernel.h:128:7: note:
expanded from macro 'WARN_ON'
                    __stringify(cond), __FILE__, __LINE__);     \
                    ^
                    ^
In file included from
/usr/local/sys/modules/drm-fbsd13-kmod/linuxkpi/gplv2/src/linux_compat.c:10:
In file included from
/usr/local/sys/modules/drm-fbsd13-kmod/linuxkpi/gplv2/include/linux/pci.h:10:
In file included from
/usr/src/sys/compat/linuxkpi/common/include/linux/pci.h:55:
In file included from
/usr/src/sys/compat/linuxkpi/common/include/linux/dmapool.h:37:
In file included from
/usr/local/sys/modules/drm-fbsd13-kmod/linuxkpi/gplv2/include/linux/device.h:4:
In file included from
/usr/src/sys/compat/linuxkpi/common/include/linux/device.h:36:
In file included from
/usr/local/sys/modules/drm-fbsd13-kmod/linuxkpi/gplv2/include/linux/kobject.h:4:
In file included from
/usr/src/sys/compat/linuxkpi/common/include/linux/kobject.h:37:
/usr/src/sys/compat/linuxkpi/common/include/linux/kref.h:118:2: error:
format specifies type 'char *' but the argument has type 'int'
[-Werror,-Wformat]
        WARN_ON(release == NULL);
        ^~~~~~~~~~~~~~~~~~~~~~~~
/usr/src/sys/compat/linuxkpi/common/include/linux/kernel.h:128:7: note:
expanded from macro 'WARN_ON'
                    __stringify(cond), __FILE__, __LINE__);     \

Are others seeing this? Any idea what's wrong? I didn't even realize that
the lkpi and drm module had been moved into the kernel build.

I mostly would like to see if something is broken in my environment before
opening a ticket. Full build log available on request.
--
Kevin Oberman, Part time kid herder and retired Network Engineer
E-mail: rkoberman@gmail.com
PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683