OpenBSD: Inclusion of -DDEBUG_STACK in src/Makefile.in results in error

[anarchitech]

On OpenBSD 7.0 --current GENERIC.MP i386, inclusion of -DDEBUG_STACK in src/Makefile.in results in an undeclared
identifier error:

cc -O2 -Wall -fomit-frame-pointer -Wno-int-to-pointer-cast
-DDEBUG_STACK -DDEBUG_USB_ENUMERATION  -c kernel.c
cc -O2 -Wall -fomit-frame-pointer -Wno-int-to-pointer-cast
-DDEBUG_STACK -DDEBUG_USB_ENUMERATION  -c engine-itc.c
cc -O2 -Wall -fomit-frame-pointer -Wno-int-to-pointer-cast
-DDEBUG_STACK -DDEBUG_USB_ENUMERATION  -c interpret.c
interpret.c:232:38: error: use of undeclared identifier 'uval'
        fprintf(stderr, "  %16llx", (uval)SP[3-i]);
                                                     ^
1 error generated.
*** Error 1 in ~/muforth/src (<sys.mk>:87 'interpret.o')

This error will impact other systems/architectures as well. (Tested and present Archlinux/AMD64 and aarch64, Termux aarch64)