Ambiguous formatter specialization in fmt/ranges.h

[vitaut]

Modular build revealed an issue in experimental fmt/ranges.h:

In module 'third-party/fmt:fmt' imported from ...:
fmt/include/fmt/format.h:2243:50: error: ambiguous partial specializations of 'formatter<folly::Range<const char *>, char, void>'
  formatter<T, typename ParseContext::char_type> f{};
                                                 ^
fmt/include/fmt/format.h:2253:21: note: in instantiation of function template specialization 'fmt::v5::internal::parse_format_specs<folly::Range<const char *>, fmt::v5::basic_parse_context<char, fmt::v5::internal::error_handler> >' requested here
      parse_funcs_{&parse_format_specs<Args, parse_context_type>...} {}
                    ^
fmt/include/fmt/format.h:2303:54: note: in instantiation of member function 'fmt::v5::internal::format_string_checker<char, fmt::v5::internal::error_handler, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, folly::Range<const char *>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::format_string_checker' requested here
  format_string_checker<Char, ErrorHandler, Args...> checker(s, eh);
                                                     ^
fmt/include/fmt/format.h:2312:17: note: in instantiation of function template specialization 'fmt::v5::internal::check_format_string<char, fmt::v5::internal::error_handler, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, folly::Range<const char *>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >' requested here
      internal::check_format_string<char, internal::error_handler, Args...>(
                ^
fmt/include/fmt/core.h:1377:13: note: in instantiation of function template specialization 'fmt::v5::internal::check_format_string<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, folly::Range<const char *>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > , S>' requested here
  internal::check_format_string<Args...>(format_str);
            ^
...: note: in instantiation of function template specialization 'fmt::v5::format<S, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int, folly::Range<const char *>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >' requested here
  return fmt::format(
              ^
fmt/include/fmt/format.h:3169:8: note: partial specialization matches [with T = folly::Range<const char *>, Char = char]
struct formatter<
       ^
fmt/include/fmt/ranges.h:262:8: note: partial specialization matches [with RangeT = folly::Range<const char *>, Char = char]
struct formatter<RangeT, Char,
       ^