Build Error on FreeBSD 12

Hi

When building gdb 8.3 for *-rtems5 targets on FreeBSD 12, we are getting
undefined errors for libiconv symbols. The messages are like this:

================================
 CXXLD  gdb
charset.o: In function `convert_between_encodings(char const*, char const*,
unsigned char const*, unsigned int,
int, obstack*, transliterations)':
charset.c:(.text+0x251): undefined reference to `libiconv_open'
charset.c:(.text+0x2df): undefined reference to `libiconv'
charset.c:(.text+0x434): undefined reference to `libiconv_close'
charset.c:(.text+0x486): undefined reference to `libiconv_close'
charset.o: In function `wchar_iterator::wchar_iterator(unsigned char
const*, unsigned int, char const*, unsigned
 int)':
charset.c:(.text+0x4f9): undefined reference to `libiconv_open'
================================

Q1: The compile line is shortened in the output so I can't tell what it is
linking command is really doing. What's the magic for having the full
command lines printed?

Q2: Does this sound familiar to anyone? We build fine on other OSes and
apparently this
doesn't happen on FreeBSD 11. Any hint is appreciated.

The config.log does show it found iconv().

Thanks.

--joel