Same issue with ThisThread::sleep_for() and “memcopy” after updating to 1.4.2.
Uninstall and reinstalled 1.4.0 but now I get TickerBase::attach error also (sleep_for error continues).
Error: L6218E: Undefined symbol mbed::TickerBase::attach(mbed::Callback<void…
Error: L6218E: Undefined symbol rtos::ThisThread::sleep_for(std::__2…
Error: L6218E: Undefined symbol std::__2::basic_string<char, std::__2::char_tra…