Comment 2 for bug 1628879

Ok, after playing around a bit more I managed to get a freeze while running in lldb. I was trying to start the simulation (which worked fine many times before) after assigning the generic opamp spice model from the simulator demos.

```
* thread #1: tid = 0x1e6956, 0x00007fff98b76f8a libsystem_kernel.dylib`__read_nocancel + 10, stop reason = signal SIGSTOP
  * frame #0: 0x00007fff98b76f8a libsystem_kernel.dylib`__read_nocancel + 10
    frame #1: 0x00007fff9e96c155 libsystem_c.dylib`_sread + 16
    frame #2: 0x00007fff9e96b769 libsystem_c.dylib`__srefill1 + 24
    frame #3: 0x00007fff9e964a60 libsystem_c.dylib`fgets + 106
    frame #4: 0x000000010c5e8beb libngspice.0.dylib`promptreturn + 109
    frame #5: 0x000000010c5e8d5b libngspice.0.dylib`out_send + 237
    frame #6: 0x000000010c5e8e04 libngspice.0.dylib`out_vprintf + 38
    frame #7: 0x000000010c5e8eb4 libngspice.0.dylib`out_printf + 148
    frame #8: 0x000000010c5c29a2 libngspice.0.dylib`inp_dodeck + 1063
    frame #9: 0x000000010c5c210b libngspice.0.dylib`inp_spsource + 4852
    frame #10: 0x000000010c5c3549 libngspice.0.dylib`create_circbyline + 223
    frame #11: 0x000000010c5a9387 libngspice.0.dylib`ngSpice_Circ + 93
    frame #12: 0x000000010be478b8 _eeschema.kiface`NGSPICE::LoadNetlist(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) + 3032
    frame #13: 0x000000010be257f2 _eeschema.kiface`SIM_PLOT_FRAME::StartSimulation() + 1170
```

doing a continue in lldb it would continue to run again.