CFLAGS='-Wl,-z,relro,-z,now -pie -fPIE -fstack-protector-all -D_FORTIFY_SOURCE=2 -O1'

clang: warning: argument unused during compilation: '-pie' [-Wunused-command-line-argument]
clang: warning: argument unused during compilation: '-pie' [-Wunused-command-line-argument]
warning: unknown warning option '-W1,-z,relro,-z,now' [-Wunknown-warning-option]