if i try to change the font using a pango context, the app aborts when i
try to draw the pango layout.

here is some example code:

Gtk::Window* pWin = NULL;  // excuse the global...it's just a test app
typedef Glib::ArrayHandle< Glib::RefPtr<Pango::FontFamily> > tFontList;

bool
draw(GdkEventExpose* pEvent)
{

    // -------------------------------------------------------------------
    // this is the only way that works and allows you to change the font:
    // -------------------------------------------------------------------
    //                                                                    
    // Glib::RefPtr<Pango::Layout> pLayout = 
    //     pWin->create_pango_layout("Pango Test Application");
    // Pango::FontDescription font("fixed");
    // pLayout->set_font_description(font); 

    // ------------------------------------------------------------------
    // broken examples below:
    // ------------------------------------------------------------------

    // this never works
    //
//  Glib::RefPtr<Pango::Context> pContext = Pango::Context::create();

    // both of these work as long as i don't call set_font_description below
    //
//  Glib::RefPtr<Pango::Context> pContext = pWin->get_pango_context();
    Glib::RefPtr<Pango::Context> pContext = pWin->create_pango_context();

    // this displays a list of all my fonts, including "fixed"
    //
    tFontList pArray = pContext->list_families();
    for (tFontList::const_iterator itr = pArray.begin();
         itr != pArray.end(); ++itr) {
         Glib::RefPtr<Pango::FontFamily> pFamily = *itr;
         std::cout << pFamily->get_name() << std::endl;
    }

    // calling set_font_description causes the app to abort when     
    // draw_layout
    // is called, saying it can't find font "fixed" or any fallbacks,
    // even though "fixed" is listed by the above code.  i've tried it
    // with many other font names and it's always the same result.
    //
    Pango::FontDescription font("fixed");        
    pContext->set_font_description(font);

    Glib::RefPtr<Pango::Layout> pLayout = Pango::Layout::create(pContext);
    pLayout->set_text("Pango Test Application");

    Glib::RefPtr<Gdk::GC> gc = pWin->get_style()->get_black_gc();
    pWin->get_window()->draw_layout(gc, 10, 10, pLayout);
}

int
main(int argc, char* argv[])
{
	Gtk::Main kit(argc, argv);

	pWin = new Gtk::Window(Gtk::WINDOW_TOPLEVEL);
	
	pWin->set_default_size(500, 100);

	pWin->signal_expose_event().connect(SigC::slot(draw));
	
	pWin->show_all();

	
	kit.run();
}