Error compiling isboot-kmod

On this CURRENT snapshot
# uname -a
FreeBSD freebsd12 12.0-CURRENT FreeBSD 12.0-CURRENT #0 r327788: Wed Jan 10
22:55:40 UTC 2018
root_at_releng3.nyi.freebsd.org:/usr/obj/usr/src/amd64.amd64/sys/GENERIC
amd64

I can't compile the kernel module isboot-kmod:
# cd /usr/ports/net/isboot-kmod && make
===>  License BSD2CLAUSE accepted by the
user

===>   isboot-kmod-0.2.13_1 depends on file: /usr/local/sbin/pkg - found
===> Fetching all distfiles required by isboot-kmod-0.2.13_1 for building
===>  Extracting for isboot-kmod-0.2.13_1
=> SHA256 Checksum OK for isboot-0.2.13.tar.gz.
===>  Patching for isboot-kmod-0.2.13_1
===>  Applying FreeBSD patches for isboot-kmod-0.2.13_1
===>  Configuring for isboot-kmod-0.2.13_1
===>  Building for isboot-kmod-0.2.13_1
--- machine ---
--- x86 ---
--- machine ---
machine -> /usr/src/sys/amd64/include
--- x86 ---
x86 -> /usr/src/sys/x86/include
--- objwarn ---
--- opt_cam.h ---
--- objwarn ---
Warning: Object directory not changed from original
/usr/ports/net/isboot-kmod/work/isboot-0.2.13/src
--- opt_cam.h ---
:> opt_cam.h
--- isboot.o ---
--- ibft.o ---
--- isboot.o ---
cc  -O2 -pipe -fno-strict-aliasing  -Werror -D_KERNEL -DKLD_MODULE
-nostdinc   -I. -I/usr/src/sys -fno-common  -fno-omit-frame-pointer
-mno-omit-leaf-frame-pointer   -MD  -MF.depe$
d.isboot.o -MTisboot.o -mcmodel=kernel -mno-red-zone -mno-mmx -mno-sse
-msoft-float  -fno-asynchronous-unwind-tables -ffreestanding -fwrapv
-fstack-protector -Wall -Wredundant-dec$
s -Wnested-externs -Wstrict-prototypes -Wmissing-prototypes -Wpointer-arith
-Winline -Wcast-qual -Wundef -Wno-pointer-sign
-D__printf__=__freebsd_kprintf__ -Wmissing-include-dirs $
fdiagnostics-show-option -Wno-unknown-pragmas
-Wno-error-tautological-compare -Wno-error-empty-body
-Wno-error-parentheses-equality -Wno-error-unused-function
-Wno-error-pointer-s$
gn -Wno-error-shift-negative-value -Wno-error-address-of-packed-member
-mno-aes -mno-avx  -std=iso9899:1999 -c isboot.c -o isboot.o
--- ibft.o ---
cc  -O2 -pipe -fno-strict-aliasing  -Werror -D_KERNEL -DKLD_MODULE
-nostdinc   -I. -I/usr/src/sys -fno-common  -fno-omit-frame-pointer
-mno-omit-leaf-frame-pointer   -MD  -MF.depe$
d.ibft.o -MTibft.o -mcmodel=kernel -mno-red-zone -mno-mmx -mno-sse
-msoft-float  -fno-asynchronous-unwind-tables -ffreestanding -fwrapv
-fstack-protector -Wall -Wredundant-decls -$
nested-externs -Wstrict-prototypes -Wmissing-prototypes -Wpointer-arith
-Winline -Wcast-qual -Wundef -Wno-pointer-sign
-D__printf__=__freebsd_kprintf__ -Wmissing-include-dirs -fdi$
gnostics-show-option -Wno-unknown-pragmas -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-error-address-of-packed-member
-mno-aes -mno-avx  -std=iso9899:1999 -c ibft.c -o ibft.o
--- iscsi.o ---
cc  -O2 -pipe -fno-strict-aliasing  -Werror -D_KERNEL -DKLD_MODULE
-nostdinc   -I. -I/usr/src/sys -fno-common  -fno-omit-frame-pointer
-mno-omit-leaf-frame-pointer   -MD  -MF.depe$
d.iscsi.o -MTiscsi.o -mcmodel=kernel -mno-red-zone -mno-mmx -mno-sse
-msoft-float  -fno-asynchronous-unwind-tables -ffreestanding -fwrapv
-fstack-protector -Wall -Wredundant-decls
-Wnested-externs -Wstrict-prototypes -Wmissing-prototypes -Wpointer-arith
-Winline -Wcast-qual -Wundef -Wno-pointer-sign
-D__printf__=__freebsd_kprintf__ -Wmissing-include-dirs -f$
iagnostics-show-option -Wno-unknown-pragmas -Wno-error-tautological-compare
-Wno-error-empty-body -Wno-error-parentheses-equality
-Wno-error-unused-function -Wno-error-pointer-sig$
 -Wno-error-shift-negative-value -Wno-error-address-of-packed-member
-mno-aes -mno-avx  -std=iso9899:1999 -c iscsi.c -o iscsi.o
In file included from iscsi.c:62:
In file included from /usr/src/sys/cam/cam_ccb.h:1035:
In file included from /usr/src/sys/cam/mmc/mmc_bus.h:5:
In file included from /usr/src/sys/dev/mmc/bridge.h:59:
/usr/src/sys/sys/bus.h:726:10: fatal error: 'device_if.h' file not found
#include "device_if.h"
         ^~~~~~~~~~~~~
1 error generated.
*** [iscsi.o] Error code 1

make[2]: stopped in /usr/ports/net/isboot-kmod/work/isboot-0.2.13/src
1 error

make[2]: stopped in /usr/ports/net/isboot-kmod/work/isboot-0.2.13/src
===> Compilation failed unexpectedly.
Try to set MAKE_JOBS_UNSAFE=yes and rebuild before reporting the failure to
the maintainer.
*** Error code 1

Stop.
make[1]: stopped in /usr/ports/net/isboot-kmod
*** Error code 1

Stop.
make: stopped in /usr/ports/net/isboot-kmod

--
Regards
Maurizio