#0  g_type_check_instance (type_instance=0x975ea20) at /build/buildd/glib2.0-2.31.16/./gobject/gtype.c:4072
        node = 0x9d9ee20
#1  0x031b5b72 in g_signal_emit_valist (instance=0x975ea20, signal_id=221, detail=0, var_args=0xbface03c "x\035F\t\340\031F\tP\350%\n\230\341\314\t\316+\034\003P\350%\n\001") at /build/buildd/glib2.0-2.31.16/./gobject/gsignal.c:2966
        _g_boolean_var_ = <optimized out>
        instance_and_params = <optimized out>
        signal_return_type = <optimized out>
        param_values = <optimized out>
        node = 0x975ea20
        i = <optimized out>
        n_params = <optimized out>
        __PRETTY_FUNCTION__ = "g_signal_emit_valist"
#2  0x031b6253 in g_signal_emit (instance=0x975ea20, signal_id=221, detail=0) at /build/buildd/glib2.0-2.31.16/./gobject/gsignal.c:3090
        var_args = 0xbface03c "x\035F\t\340\031F\tP\350%\n\230\341\314\t\316+\034\003P\350%\n\001"
#3  0x083b0603 in bamf_matcher_on_active_window_changed (proxy=0x9cce198, old_path=0xa18a1b8 "/org/ayatana/bamf/window58720260", new_path=0xa251988 "/org/ayatana/bamf/window23068676", matcher=0x975ea20) at /build/buildd/bamf-0.2.108/./lib/libbamf/bamf-matcher.c:194
        old_view = 0x9461d78
        new_view = <optimized out>
#4  0x083b7baa in bamf_marshal_VOID__STRING_STRING (closure=0x9d360f0, return_value=0x0, n_param_values=3, param_values=0xa25e850, invocation_hint=0xbface210, marshal_data=0x0) at bamf-marshal.c:84
        callback = 0x83b0590 <bamf_matcher_on_active_window_changed>
        cc = 0x9d360f0
        data1 = <optimized out>
        data2 = <optimized out>
        __PRETTY_FUNCTION__ = "bamf_marshal_VOID__STRING_STRING"
#5  0x071e117a in ?? ()
No symbol table info available.
#6  0x09d360f0 in ?? ()
No symbol table info available.
Backtrace stopped: previous frame inner to this frame (corrupt stack?)