Using glibc-2.15, the copyright notice in argp.h goes up to 2009, yet the symbol OPTION_NO_TRANS is not defined there (and presumably not processed by any of the argp code).
Was this removed again sometime later? Please refer to this patch from 2004 for details: http://lists.gnu.org/archive/html/bug-gnulib/2004-09/msg00184.html