Warning escalated to error when cross-compiling with arm-linux-gnueabihf-gcc version 9.3.0

[Th3Fanbus]

I'm forwarding someone else's report. There's a warning which breaks building because of -Werror. Build log without -Werror:

[~/Projects/iotools]>ARCHFLAGS="-mfloat-abi=hard" CROSS_COMPILE=arm-linux-gnueabihf- make arm-linux-gnueabihf-gcc -Wall -D_GNU_SOURCE -DVER_MAJOR=1 -DVER_MINOR=6 -mfloat-abi=hard -static -O0 -ggdb -c -o cmos_rw.o cmos_rw.c arm-linux-gnueabihf-gcc -Wall -D_GNU_SOURCE -DVER_MAJOR=1 -DVER_MINOR=6 -mfloat-abi=hard -static -O0 -ggdb -c -o commands.o commands.c arm-linux-gnueabihf-gcc -Wall -D_GNU_SOURCE -DVER_MAJOR=1 -DVER_MINOR=6 -mfloat-abi=hard -static -O0 -ggdb -c -o io_rw.o io_rw.c arm-linux-gnueabihf-gcc -Wall -D_GNU_SOURCE -DVER_MAJOR=1 -DVER_MINOR=6 -mfloat-abi=hard -static -O0 -ggdb -c -o logic.o logic.c arm-linux-gnueabihf-gcc -Wall -D_GNU_SOURCE -DVER_MAJOR=1 -DVER_MINOR=6 -mfloat-abi=hard -static -O0 -ggdb -c -o misc.o misc.c In file included from misc.c:33: misc.c:261:29: warning: ‘cpuid_params’ defined but not used [-Wunused-const-variable=] 261 | MAKE_PREREQ_PARAMS_VAR_ARGS(cpuid_params, 3, 4, "<cpu> <function> [index]", 0); | ^~~~~~~~~~~~ commands.h:77:36: note: in definition of macro ‘MAKE_PREREQ_PARAMS_VAR_ARGS’ 77 | static const struct prereq_params name_ = \ | ^~~~~ arm-linux-gnueabihf-gcc -Wall -D_GNU_SOURCE -DVER_MAJOR=1 -DVER_MINOR=6 -mfloat-abi=hard -static -O0 -ggdb -c -o mmio_rw.o mmio_rw.c arm-linux-gnueabihf-gcc -Wall -D_GNU_SOURCE -DVER_MAJOR=1 -DVER_MINOR=6 -mfloat-abi=hard -static -O0 -ggdb -c -o msr.o msr.c arm-linux-gnueabihf-gcc -Wall -D_GNU_SOURCE -DVER_MAJOR=1 -DVER_MINOR=6 -mfloat-abi=hard -static -O0 -ggdb -c -o pci_rw.o pci_rw.c arm-linux-gnueabihf-gcc -Wall -D_GNU_SOURCE -DVER_MAJOR=1 -DVER_MINOR=6 -mfloat-abi=hard -static -O0 -ggdb -c -o scom.o scom.c arm-linux-gnueabihf-gcc -Wall -D_GNU_SOURCE -DVER_MAJOR=1 -DVER_MINOR=6 -mfloat-abi=hard -static -O0 -ggdb -c -o smbus_rw.o smbus_rw.c arm-linux-gnueabihf-gcc -Wall -D_GNU_SOURCE -DVER_MAJOR=1 -DVER_MINOR=6 -mfloat-abi=hard -static -O0 -ggdb -c -o iotools.o iotools.c arm-linux-gnueabihf-gcc -Wall -D_GNU_SOURCE -DVER_MAJOR=1 -DVER_MINOR=6 -mfloat-abi=hard -static -O0 -ggdb -o iotools iotools.o cmos_rw.o commands.o io_rw.o logic.o misc.o mmio_rw.o msr.o pci_rw.o scom.o smbus_rw.o