ld: library not found for -lcrt0.o on OSX 10.6 with gcc/clang -static flag

This won’t work. From the man page for gcc:

This option will not work on Mac OS X unless all libraries (including libgcc.a) have also been compiled with -static. Since neither a static version of libSystem.dylib nor crt0.o are provided, this option is not useful to most people.