Greg woods writes:

    Is there no way to get this to fail at link time, instead of run-time?

No.  ld(1) looks for libc.so, not libc.so.12.  I suggest you familiarize
yourself with how shared library versioning is actually done in ELF.  It's
not anything like the mechanism used in a.out, not in the slightest.

        -- Jason R. Thorpe <thorpej@nas.nasa.gov>