I am trying to build someone else's QT project that they built and created on Linux, I am trying to build it on a Mac.

However, I am getting the error message "Undefined symbols for architecture x86_64".

error message:

vieworder.cpp.o:-1: error: Undefined symbols for architecture x86_64:
  "pqxx::row::row(pqxx::result const&, int)", referenced from:
      pqxx::const_result_iterator::const_result_iterator(pqxx::result const*, int) in vieworder.cpp.o
  "pqxx::internal::check_pqxx_version_7_6()", referenced from:
      pqxx::check_version() in main.cpp.o
  "pqxx::field::name() const", referenced from:
      ViewOrder::on_statusBtn_clicked() in vieworder.cpp.o
  "pqxx::field::c_str() const", referenced from:
      pqxx::field::view() const in homewindow.cpp.o
      ViewOrder::on_historyBtn_clicked() in vieworder.cpp.o
      ViewOrder::on_statusBtn_clicked() in vieworder.cpp.o

Thanks!