[libcalamaresui] Report on failed module loading

- Collect the failed modules, instead of bailing out on the first one
   (this also prevents crashes caused by quit() called from a timer).
 - Introduce a slot to report on failed module loading (no UI yet).

src/calamares/CalamaresApplication.cpp

@@ -335,6 +335,8 @@ CalamaresApplication::initView()
 
     connect( m_moduleManager, &Calamares::ModuleManager::modulesLoaded,
              this, &CalamaresApplication::initViewSteps );
+    connect( m_moduleManager, &Calamares::ModuleManager::modulesFailed,
+             this, &CalamaresApplication::initFailed );
 
     m_moduleManager->loadModules();
 
@@ -356,6 +358,12 @@ CalamaresApplication::initViewSteps()
     cDebug() << "STARTUP: Window now visible and ProgressTreeView populated";
 }
 
+void
+CalamaresApplication::initFailed(const QStringList& l)
+{
+    cError() << "STARTUP: failed modules are" << l;
+    m_mainwindow->show();
+}
 
 void
 CalamaresApplication::initJobQueue()

src/calamares/CalamaresApplication.h

@@ -70,6 +70,7 @@ public:
 private slots:
     void initView();
     void initViewSteps();
+    void initFailed( const QStringList& l );
 
 private:
     void initQmlPath();

src/libcalamaresui/modulesystem/ModuleManager.cpp

@@ -181,6 +181,7 @@ ModuleManager::loadModules()
 
     QTimer::singleShot( 0, this, [ this ]()
     {
+        QStringList failedModules;
         Settings::InstanceDescriptionList customInstances =
                 Settings::instance()->customModuleInstances();
 
@@ -201,8 +202,8 @@ ModuleManager::loadModules()
                 {
                     cError() << "Wrong module entry format for module" << moduleEntry << '.'
                         << GOODBYE;
-                    qApp->exit( 1 );
+                    failedModules.append( moduleEntry );
-                    return;
+                    continue;
                 }
                 moduleName = moduleEntrySplit.first();
                 instanceId = moduleEntrySplit.last();
@@ -214,8 +215,8 @@ ModuleManager::loadModules()
                     cError() << "Module" << moduleName << "not found in module search paths."
                         << Logger::DebugList( m_paths )
                         << GOODBYE;
-                    qApp->exit( 1 );
+                    failedModules.append( moduleName );
-                    return;
+                    continue;
                 }
 
                 if ( moduleName != instanceId ) //means this is a custom instance
@@ -228,8 +229,8 @@ ModuleManager::loadModules()
                     {
                         cError() << "Custom instance" << moduleEntry << "not found in custom instances section."
                             << GOODBYE;
-                        qApp->exit( 1 );
+                        failedModules.append( moduleEntry );
-                        return;
+                        continue;
                     }
                 }
 
@@ -251,8 +252,8 @@ ModuleManager::loadModules()
                 {
                     cError() << "Module" << instanceKey << "exists but not loaded."
                              << GOODBYE;
-                    qApp->exit( 1 );
+                    failedModules.append( instanceKey );
-                    return;
+                    continue;
                 }
 
                 if ( thisModule && thisModule->isLoaded() )
@@ -270,7 +271,8 @@ ModuleManager::loadModules()
                     {
                         cError() << "Module" << instanceKey << "cannot be created from descriptor" << configFileName
                             << GOODBYE;
-                        qApp->exit( 1 );
+                        failedModules.append( instanceKey );
+                        continue;
                     }
                     // If it's a ViewModule, it also appends the ViewStep to the ViewManager.
                     thisModule->loadSelf();
@@ -279,7 +281,8 @@ ModuleManager::loadModules()
                     {
                         cError() << "Module" << instanceKey << "loading FAILED"
                             << GOODBYE;
-                        qApp->exit( 1 );
+                        failedModules.append( instanceKey );
+                        continue;
                     }
                 }
 
@@ -300,6 +303,9 @@ ModuleManager::loadModules()
                 }
             }
         }
+        if ( !failedModules.isEmpty() )
+            emit modulesFailed( failedModules );
+        else
             emit modulesLoaded();
     } );
 }

src/libcalamaresui/modulesystem/ModuleManager.h

@@ -82,7 +82,8 @@ public:
 
 signals:
     void initDone();
-    void modulesLoaded();
+    void modulesLoaded();  /// All of the modules were loaded successfully
+    void modulesFailed( QStringList );   /// .. or not
 
 private slots:
     void doInit();