'configure' sets HAVE_GETOPT and HAVE_GETOPT_H, but the code doesn't honour these defines.
IRIX, for example, has /usr/include/getopt.h but this isn't GNU-compatible. This means that scponly fails to build due to the references to 'struct option' from line 88 of scponly.c.
This is a regression from version 4.6, which used 'cmd_arg_t' and did build successfully on IRIX.
(Also, on this platform, 'bzero' is defined in strings.h rather than string.h, so this should really be checked for and included.)