gdb - undefined reference to `std::__1::codecvt<char, char, int>::id'

[Roy Marples <roy%marples.name@localhost>]

#      link  gdb/gdb
/usr/tools/bin/x86_64--netbsd-clang++    --sysroot=/ -Wl,--warn-shared-textrel 
-Wl,-z,relro   -pie      -o gdb  gdb.o  -Wl,-rpath-link,/lib  -L=/lib 
-L/home/roy/src/hg/src/external/gpl3/gdb/lib/libgdb/obj.amd64 -lgdb 
-L/home/roy/src/hg/src/external/gpl3/gdb/lib/libopcodes/obj.amd64 -lopcodes 
-L/home/roy/src/hg/src/external/gpl3/gdb/lib/libbfd/obj.amd64 -lbfd 
-L/home/roy/src/hg/src/external/gpl3/gdb/lib/libdecnumber/obj.amd64 -ldecnumber 
-L/home/roy/src/hg/src/external/gpl3/gdb/lib/libgdbsupport/obj.amd64 
-lgdbsupport  -L/home/roy/src/hg/src/external/gpl3/gdb/lib/libctf/obj.amd64 
-lctf  -L/home/roy/src/hg/src/external/gpl3/gdb/lib/libgnulib/obj.amd64 -lgnulib 
 -L/home/roy/src/hg/src/external/gpl3/gdb/lib/libreadline/obj.amd64 -lreadline 
-lterminfo  -L/home/roy/src/hg/src/external/gpl3/gdb/lib/libiberty/obj.amd64 
-liberty -lexpat -llzma -lz -lcurses -lintl -lm -lkvm -lutil
/usr/tools/bin/x86_64--netbsd-ld: 
/home/roy/src/hg/src/external/gpl3/gdb/lib/libgdb/obj.amd64/libgdb.a(string_view-selftests.o): 
in function `std::__1::basic_filebuf<char, std::__1::char_traits<char> 
>::basic_filebuf()':
string_view-selftests.c:(.text._ZNSt3__113basic_filebufIcNS_11char_traitsIcEEEC2Ev[_ZNSt3__113basic_filebufIcNS_11char_traitsIcEEEC2Ev]+0x94): 
undefined reference to `std::__1::codecvt<char, char, int>::id'
/usr/tools/bin/x86_64--netbsd-ld: 
string_view-selftests.c:(.text._ZNSt3__113basic_filebufIcNS_11char_traitsIcEEEC2Ev[_ZNSt3__113basic_filebufIcNS_11char_traitsIcEEEC2Ev]+0xc4): 
undefined reference to `std::__1::codecvt<char, char, int>::id'
/usr/tools/bin/x86_64--netbsd-ld: 
/home/roy/src/hg/src/external/gpl3/gdb/lib/libgdb/obj.amd64/libgdb.a(string_view-selftests.o): 
in function `std::__1::basic_filebuf<char, std::__1::char_traits<char> 
>::imbue(std::__1::locale const&)':
string_view-selftests.c:(.text._ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE5imbueERKNS_6localeE[_ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE5imbueERKNS_6localeE]+0x13): 
undefined reference to `std::__1::codecvt<char, char, int>::id'
x86_64--netbsd-clang: error: linker command failed with exit code 1 (use -v to 
see invocation)
*** Error code 1

What went wrong?
My very limited knowledge of C++ and google foo says codecvt should be part of 
libc++?

Roy