Nvidia driver cannot compile on FreeBSD 12.0

[Unga]

Hi all
I tried to install NVIDIA-FreeBSD-x86_64-418.56 display driver but I get following compilation error:
# make install===> src (install)===> src/nvidia (install)cc  -O2 -pipe -DNV_VERSION_STRING=\"418.56\" -D__KERNEL__ -DNVRM -Wno-unused-function -Wuninitialized -O2 -fno-strict-aliasing -mno-red-zone -mcmodel=kernel -UDEBUG -U_DEBUG -DNDEBUG -Werror=undef  -Werror -D_KERNEL -DKLD_MODULE -nostdinc  -I. -I../common/inc -I. -I/usr/src/sys -I/usr/src/sys/contrib/ck/include -fno-common  -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer    -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 -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-sign -Wno-error-shift-negative-value -Wno-address-of-packed-member  -mno-aes -mno-avx  -std=iso9899:1999 -c nvidia_acpi.c -o nvidia_acpi.oIn file included from nvidia_acpi.c:12:./os-interface.h:27:10: fatal error: 'stdarg.h' file not found#include <stdarg.h>         ^~~~~~~~~~1 error generated.

My OS:# uname -aFreeBSD unga 12.0-RELEASE FreeBSD 12.0-RELEASE r341666 GENERIC  amd64
I used to have a previous version of Nvidia driver running well on FreeBSD 11.2 on the same machine.
Any idea?
Best regardsUnga