Fix some more classic GJS/GS weirdness

panelManager.js

@@ -387,7 +387,8 @@ var PanelManager = class {
                 this.bind_property('opacity', view, 'opacity', GObject.BindingFlags.SYNC_CREATE);
                 this.add_child(view);
             } else {
-                view = new SecondaryMonitorDisplay(i,
+                // todo exorcise this after the GS 42 release
+                view = new ProxySecondaryMonitorDisplay(i,
                     this._controls,
                     this._scrollAdjustment,
                     this._fitModeAdjustment,
@@ -540,6 +541,15 @@ var PanelManager = class {
     }
 };
 
+// No idea why atm, but we need the import at the top of this file and this
+// "proxy" class, otherwise SecondaryMonitorDisplay can't be used ¯\_(ツ)_/¯
+var ProxySecondaryMonitorDisplay = GObject.registerClass({
+}, class ProxySecondaryMonitorDisplay extends imports.ui.workspacesView.SecondaryMonitorDisplay {
+    _init(...params) {
+        super._init(...params)
+    }
+});
+
 // This class drives long-running icon animations, to keep them running in sync
 // with each other.
 var IconAnimator = class {