cc -O2 -pipe  -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations complex/imaginary.c -o complex/imaginary -D_POSIX_C_SOURCE=202405L  -lm -lpthread 
complex/imaginary.c:4:2: error: "imaginary is not defined"
#error "imaginary is not defined"
 ^
1 error generated.