cc -O2 -pipe -pthread -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations limits/POSIX_REC_XFER_ALIGN.c -o limits/POSIX_REC_XFER_ALIGN -D_POSIX_C_SOURCE=202405L -lm -lpthread limits/POSIX_REC_XFER_ALIGN.c:5:2: error: "POSIX_REC_XFER_ALIGN is not defined" #error "POSIX_REC_XFER_ALIGN is not defined" ^ 1 error generated.