pingus @0.8.0-20180714: Undefined symbols Json::Value::Value(...) Json::Reader::parse(...)

[ryandesign (Ryan Carsten Schmidt)]

​pingus does not build:

Undefined symbols for architecture i386:
  "Json::Value::Value(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)", referenced from:
      JsonWriterImpl::write_string(char const*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) in libpingus.a(json_writer_impl.cpp.o)
  "Json::Reader::parse(std::__1::basic_istream<char, std::__1::char_traits<char> >&, Json::Value&, bool)", referenced from:
      Reader::parse(std::__1::basic_istream<char, std::__1::char_traits<char> >&) in libpingus.a(reader.cpp.o)
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)