I got a copy of preprocessed sources from bryan d. o'connor. Here's what seems to be the problem:
* <config.h> has "#define __GETOPT_PREFIX rpl_" as expected. * unexmacosx.c includes the Gnulib <unistd.h>. * The Gnulib <unistd.h> includes the system unistd.h, which declares the getopt-related names itself (without including anything) and then finishes. * The Gnulib <unistd.h> then includes the Gnulib <getopt.h>. * The Gnulib <getopt.h> includes the system getopt.h. * The system getopt.h includes the Gnulib <unistd.h>. * This inner Gnulib <unistd.h> does nothing, and finishes. * The system getopt.h declares 'struct option' and other stuff, and finishes. * The Gnulib <getopt.h> then does this: #if defined __GETOPT_PREFIX && !defined __need_getopt # if !@HAVE_GETOPT_H@ # include <stdlib.h> # include <stdio.h> # include <unistd.h> # endif # undef __need_getopt ... # undef option # define __GETOPT_CONCAT(x, y) x ## y # define __GETOPT_XCONCAT(x, y) __GETOPT_CONCAT (x, y) # define __GETOPT_ID(y) __GETOPT_XCONCAT (__GETOPT_PREFIX, y) ... # define option __GETOPT_ID (option) ... #endif * This should "#define option rpl_option", but apparently it doesn't. * Presumably __GETOPT_PREFIX is defined, but __need_getopt is also defined, so the entire #if is skipped. * And when Gnulib <getopt.h> declares a 'struct option', this clashes with the 'struct option' declared in the system getopt.h. If my analysis is right, we need to figure out why __need_getopt is defined. Can you send the output of the following? cd emacs grep -r __need_getopt . /usr/include PS. This all seems to be a case where we should be using Gnulib's identifier replacement mechanism, but I don't understand it that well and if memory serves it doesn't work with struct tags anyway.