diff -rupN --no-dereference OpenSceneGraph-OpenSceneGraph-3.6.5/examples/osgviewerWX/osgviewerWX.cpp OpenSceneGraph-OpenSceneGraph-3.6.5-new/examples/osgviewerWX/osgviewerWX.cpp
--- OpenSceneGraph-OpenSceneGraph-3.6.5/examples/osgviewerWX/osgviewerWX.cpp	2020-01-31 12:03:07.000000000 +0100
+++ OpenSceneGraph-OpenSceneGraph-3.6.5-new/examples/osgviewerWX/osgviewerWX.cpp	2021-11-13 21:34:02.963773980 +0100
@@ -91,6 +91,11 @@ bool wxOsgApp::OnInit()
     return true;
 }
 
+void __attribute__ ((constructor)) force_x11()
+{
+    setenv("GDK_BACKEND", "x11", 1);
+}
+
 IMPLEMENT_APP(wxOsgApp)
 
 BEGIN_EVENT_TABLE(MainFrame, wxFrame)