N.B. I've found pdb files related to the GTK DLLs
        distributed as part of the hexchat gtk-win32 project (
https://github.com/hexchat/gtk-win32).
        
        
        Executing with these in place, the VS 2015 debugger is
          showing me that there is an intermittent issue when
          "pango_layout_clear_lines" is called.
        
        
        Ultimately a NULL pointer is passed to glib's
          "magazine_chain_prepare_fields" function.
        
        
        The issue can be recreated by creating and destroying a UI
          dialogue a specific number of times. Each text block in the UI
          dialogue is rendered by creating and destroying PangoLayout
          and PangoFontDescription objects.
          
          As this is an intermittent issue, and at a glib memory
          management level, I am not sure how to proceed.
          
          Any advice would be appreciated.