(automake) How do I force an object file to be rebuilt every time?

Hi,

I've got a project that includes a version number that needs to be
emitted on demand.  I want to put that version number by itself in a
one line C file that other objects can link to (so the version can
change without having to rebuild any particular file).  How do I get
that one file (version_globals.c) to rebuild every time a build is
called using configure.ac, makefile.am, etc?

Thanks in advance!

   -- Rich --