Improve error message when capture stream fails

Rather than just guessing at the cause of the error, include the actual
error string from PortAudio.

src/AudioIO.cpp

@@ -1826,6 +1826,11 @@ bool AudioIO::StartPortAudioStream(double sampleRate,
    return (mLastPaError == paNoError);
 }
 
+wxString AudioIO::LastPaErrorString()
+{
+   return wxString::Format(wxT("%d %s."), (int) mLastPaError, Pa_GetErrorText(mLastPaError));
+}
+
 void AudioIO::StartMonitoring(double sampleRate)
 {
    if ( mPortStreamV19 || mStreamToken )

src/AudioIO.h

@@ -729,6 +729,10 @@ private:
    volatile double     mLastRecordingOffset;
    PaError             mLastPaError;
 
+public:
+   wxString            LastPaErrorString();
+private:
+
    AudacityProject    *mOwningProject;
    wxWeakRef<MeterPanel> mInputMeter{};
    MeterPanel         *mOutputMeter;

src/toolbars/ControlToolBar.cpp

@@ -876,7 +876,7 @@ void ControlToolBar::StopPlaying(bool stopStream /* = true*/)
       if( meter ) {
          meter->Clear();
       }
-      
+
       meter = project->GetCaptureMeter();
       if( meter ) {
          meter->Clear();
@@ -1312,9 +1312,8 @@ bool ControlToolBar::DoRecord(AudacityProject &project,
          CancelRecording();
 
          // Show error message if stream could not be opened
-         ShowErrorDialog(this, _("Error"),
-                         _("Error opening sound device.\nTry changing the audio host, recording device and the project sample rate."),
-                         wxT("Error_opening_sound_device"));
+         wxString msg = wxString::Format(_("Error opening recording device.\nError code: %s"), gAudioIO->LastPaErrorString());
+         ShowErrorDialog(this, _("Error"), msg, wxT("Error_opening_sound_device"));
       }
    }