r255449: kernel compilation fails due to : cc: error: no input files

I get this error when trying to compile a kernel on CURRENT r244449:


[...]
make[2]: Unclosed substitution for COMPILER_TYPE (/ missing)
cc  -c -O3 -fno-strict-aliasing -march=native -std=c99 -Wall
-Wredundant-decls -Wnested-externs -Wstrict-prototypes
-Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual -Wundef
-Wno-pointer-sign -fformat-extensions -Wmissing-include-dirs
-fdiagnostics-show-option -Wno-error-tautological-compare
-Wno-error-empty-body -Wno-error-parentheses-equality -I.
-I/usr/src/sys -I/usr/src/sys/contrib/altq
-I/usr/src/sys/contrib/libfdt -D_KERNEL -DHAVE_KERNEL_OPTION_HEADERS
-include opt_global.h -fno-omit-frame-pointer
-mno-omit-leaf-frame-pointer -mno-aes -mno-avx -mcmodel=kernel
-mno-red-zone -mno-mmx -mno-sse -msoft-float
-fno-asynchronous-unwind-tables -ffreestanding -fstack-protector
-Werror  -mmmx -msse cc: error: no input files *** Error code 1


Regards,
Oliver