Minimal error messages for failing to load non-Nyquist effects

src/effects/LoadEffects.cpp

@@ -322,6 +322,7 @@ bool BuiltinEffectsModule::RegisterPlugin(PluginManagerInterface & pm,
       return true;
    }
 
+   errMsg = _("Unknown built-in effect name");
    return false;
 }
 

src/effects/VST/VSTEffect.cpp

@@ -502,7 +502,8 @@ bool VSTEffectsModule::RegisterPlugin(PluginManagerInterface & pm,
       catch (...)
       {
          wxLogMessage(_("VST plugin registration failed for %s\n"), path.c_str());
-         return false;
+         valid = false;
+         break;
       }
 
       wxString output;
@@ -631,6 +632,9 @@ bool VSTEffectsModule::RegisterPlugin(PluginManagerInterface & pm,
       }
    }
 
+   if (!valid)
+      errMsg = _("Could not load the library");
+
    return valid;
 }
 

src/effects/audiounits/AudioUnitEffect.cpp

@@ -180,12 +180,16 @@ bool AudioUnitEffectsModule::RegisterPlugin(PluginManagerInterface & pm,
    AudioComponent component = FindAudioUnit(path, name);
    if (component == NULL)
    {
+      errMsg = _("Could not find component");
       return false;
    }
 
    AudioUnitEffect effect(path, name, component);
    if (!effect.SetHost(NULL))
    {
+      // TODO:  Is it worth it to discriminate all the ways SetHost might
+      // return false?
+      errMsg = _("Could not initialize component");
       return false;
    }
 

src/effects/ladspa/LadspaEffect.cpp

@@ -214,6 +214,7 @@ bool LadspaEffectsModule::RegisterPlugin(PluginManagerInterface & pm,
    // causes duplicate menu entries to appear.
    wxFileName ff(path);
    if (ff.GetName().CmpNoCase(wxT("vst-bridge")) == 0) {
+      errMsg = _("Audacity no longer uses vst-bridge");
       return false;
    }
 
@@ -241,6 +242,11 @@ bool LadspaEffectsModule::RegisterPlugin(PluginManagerInterface & pm,
             if (effect.SetHost(NULL)) {
                pm.RegisterPlugin(this, &effect);
             }
+            else {
+               // If pm.RegisterPlugin is skipped, be sure to report error
+               index = 0;
+               break;
+            }
          }
       }
    }
@@ -257,6 +263,9 @@ bool LadspaEffectsModule::RegisterPlugin(PluginManagerInterface & pm,
    wxSetWorkingDirectory(saveOldCWD);
    hadpath ? wxSetEnv(wxT("PATH"), envpath) : wxUnsetEnv(wxT("PATH"));
 
+   if (index == 0)
+      errMsg = _("Could not load the library");
+
    return index > 0;
 }
 

src/effects/lv2/LoadLV2.cpp

@@ -247,18 +247,18 @@ bool LV2EffectsModule::RegisterPlugin(PluginManagerInterface & pm,
 {
    errMsg.clear();
    const LilvPlugin *plug = GetPlugin(path);
-   if (!plug)
+   if (plug)
    {
-      return false;
+      LV2Effect effect(plug);
+      if (effect.SetHost(NULL))
+      {
+         pm.RegisterPlugin(this, &effect);
+         return true;
+      }
    }
 
-   LV2Effect effect(plug);
-   if (effect.SetHost(NULL))
-   {
-      pm.RegisterPlugin(this, &effect);
-   }
-
-   return true;
+   errMsg = _("Could not load the library");
+   return false;
 }
 
 bool LV2EffectsModule::IsPluginValid(const wxString & path, bool bFast)

src/effects/vamp/LoadVamp.cpp

@@ -215,6 +215,7 @@ bool VampEffectsModule::RegisterPlugin(PluginManagerInterface & pm,
       return true;
    }
 
+   errMsg = _("Could not load the library");
    return false;
 }