mcp@mcp:~/Lab$ cat Makefile
CC=gcc-10
all:	t1 t2 t3

t1:	test.c
	${CC} -isystem /usr/include/arm-linux-gnueabihf/sys test.c -o t1

t2:	test.c
	${CC} -I/usr/include/arm-linux-gnueabihf/sys/ test.c -o t2

t3:	test.c
	${CC} test.c -o t3

clean:
	rm -rf t1 t2 t3 *.o
mcp@mcp:~/Lab$ cat test.c
#include <stdio.h>

#include <time.h>

struct timeval t1;


int main(int argc, char argv[])
{
	printf("yo.\n");
}