"gcc -o conftest -I/usr/include/x86_64-linux-gnu/ruby-2.1.0 -I/usr/include/ruby-2.1.0/ruby/backward -I/usr/include/ruby-2.1.0 -I. -D_FORTIFY_SOURCE=2   -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -fPIC conftest.c  -L. -L/usr/lib/x86_64-linux-gnu -L. -Wl,-z,relro -L/build/ruby2.1-38uxh7/ruby2.1-2.1.3/debian/lib -fstack-protector -rdynamic -Wl,-export-dynamic     -lruby-2.1  -lpthread -lgmp -ldl -lcrypt -lm   -lc"
gcc: error: unrecognized command line option ‘-fstack-protector-strong’
checked program was:
/* begin */
1: #include "ruby.h"
2:
3: int main(int argc, char **argv)
4: {
5:   return 0;
6: }
/* end */