Error messages for failing to load Nyquist effects

src/effects/nyquist/LoadNyquist.cpp

@@ -219,6 +219,7 @@ bool NyquistEffectsModule::RegisterPlugin(PluginManagerInterface & pm,
       return true;
    }
 
+   errMsg = effect.InitializationError();
    return false;
 }
 

src/effects/nyquist/Nyquist.cpp

@@ -170,6 +170,9 @@ NyquistEffect::NyquistEffect(const wxString &fName)
    mName = mFileName.GetName();
    mFileModified = mFileName.GetModificationTime();
    ParseFile();
+
+   if (!mOK && mInitError.empty())
+      mInitError = _("Ill-formed Nyquist plug-in header");
 }
 
 NyquistEffect::~NyquistEffect()
@@ -1595,6 +1598,10 @@ void NyquistEffect::Parse(const wxString &line)
       if (v < 1 || v > 4) {
          // This is an unsupported plug-in version
          mOK = false;
+         mInitError.Format(
+            _("This version of Audacity does not support Nyquist plug-in version %ld"),
+            v
+         );
          return;
       }
       mVersion = (int) v;
@@ -1799,6 +1806,7 @@ bool NyquistEffect::ParseProgram(wxInputStream & stream)
 {
    if (!stream.IsOk())
    {
+      mInitError = _("Could not open file");
       return false;
    }
 
@@ -1851,6 +1859,8 @@ For SAL, use a return statement such as:\n\treturn *track* * 0.1\n\
 or for LISP, begin with an open parenthesis such as:\n\t(mult *track* 0.1)\n ."),
                    _("Error in Nyquist code"),
                    wxOK | wxCENTRE);
+      /* i18n-hint: refers to programming "languages" */
+      mInitError = _("Could not determine language");
       return false;
       // Else just throw it at Nyquist to see what happens
    }

src/effects/nyquist/Nyquist.h

@@ -129,6 +129,7 @@ private:
    bool TransferDataFromEffectWindow();
 
    bool IsOk();
+   const wxString &InitializationError() const { return mInitError; }
 
    static wxArrayString GetNyquistSearchPath();
 
@@ -191,6 +192,7 @@ private:
     */
    bool              mIsPrompt;
    bool              mOK;
+   wxString          mInitError;
    wxString          mInputCmd; // history: exactly what the user typed
    wxString          mCmd;      // the command to be processed
    wxString          mName;   ///< Name of the Effect (untranslated)