Mac now fails to build because of libiconv

[Paul Koning <paulkoning at comcast dot net>]

It's been a few months since I tried to build GCC on my Mac, and in earlier tries it worked fine.  I have a log from 20-Sep-2017 that shows success.

But currently when I do the same configs as before, I get failures about _iconv being undefined.  This is in spite of the fact that I have libiconv installed, and just to be sure, told configure where to find it (--with-libiconv=/usr/local)

g++    -g -O2 -DIN_GCC  -DCROSS_DIRECTORY_STRUCTURE  -fno-strict-aliasing -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wmissing-format-attribute -Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -fno-common  -DHAVE_CONFIG_H -Wl,-no_pie  -o cc1 c/c-lang.o c-family/stub-objc.o attribs.o c/c-errors.o c/c-decl.o c/c-typeck.o c/c-convert.o c/c-aux-info.o c/c-objc-common.o c/c-parser.o c/c-fold.o c/gimple-parser.o c-family/c-common.o c-family/c-cppbuiltin.o c-family/c-dump.o c-family/c-format.o c-family/c-gimplify.o c-family/c-indentation.o c-family/c-lex.o c-family/c-omp.o c-family/c-opts.o c-family/c-pch.o c-family/c-ppoutput.o c-family/c-pragma.o c-family/c-pretty-print.o c-family/c-semantics.o c-family/c-ada-spec.o c-family/c-ubsan.o c-family/known-headers.o c-family/c-attribs.o c-family/c-warn.o c-family/c-spellcheck.o default-c.o \
	  cc1-checksum.o libbackend.a main.o libcommon-target.a libcommon.a ../libcpp/libcpp.a ../libdecnumber/libdecnumber.a libcommon.a ../libcpp/libcpp.a ./../intl/libintl.a -liconv  ../libbacktrace/.libs/libbacktrace.a ../libiberty/libiberty.a ../libdecnumber/libdecnumber.a   -L/usr/local/lib -L/usr/local/lib -L/usr/local/lib -lmpc -lmpfr -lgmp   -L./../zlib -lz
Undefined symbols for architecture x86_64:
  "_iconv", referenced from:
      convert_using_iconv(void*, unsigned char const*, unsigned long, _cpp_strbuf*) in libcpp.a(charset.o)
      __nl_find_msg in libintl.a(dcigettext.o)
     (maybe you meant: __Z14cpp_init_iconvP10cpp_reader, __cpp_destroy_iconv )
  "_iconv_close", referenced from:
      __cpp_destroy_iconv in libcpp.a(charset.o)
      __cpp_convert_input in libcpp.a(charset.o)
      __nl_free_domain_conv in libintl.a(loadmsgcat.o)
  "_iconv_open", referenced from:
      init_iconv_desc(cpp_reader*, char const*, char const*) in libcpp.a(charset.o)
      __nl_init_domain_conv in libintl.a(loadmsgcat.o)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Not only that, but if I configure --without-libiconv, I get the exact same error, i.e., that configure switch has no effect.

Any suggestions?

	paul