#0  0x000000000054ba0b in setup_context (registry=<synthetic pointer>, module=<synthetic pointer>, lineno=<synthetic pointer>, filename=<synthetic pointer>, stack_level=1) at ../Python/_warnings.c:449
  [Error: ../Python/_warnings.c was not found in source tree]
#1  do_warn.29446 (message=message@entry="IA__gtk_widget_style_get: assertion `GTK_IS_WIDGET (widget)' failed", category=category@entry=<type at remote 0x23021f0>, stack_level=stack_level@entry=1) at ../Python/_warnings.c:594
  [Error: ../Python/_warnings.c was not found in source tree]
#2  0x00000000004cb8e2 in PyErr_WarnEx (category=<type at remote 0x23021f0>, text=<optimized out>, stack_level=1) at ../Python/_warnings.c:720
  [Error: ../Python/_warnings.c was not found in source tree]
#3  0x00007fb8f6023284 in _log_func (log_domain=<optimized out>, log_level=G_LOG_LEVEL_CRITICAL, message=0x2610e00 "IA__gtk_widget_style_get: assertion `GTK_IS_WIDGET (widget)' failed", user_data=0x23021f0) at /build/buildd/pygobject-2-2.28.6/gobject/gobjectmodule.c:2353
  [Error: /build/buildd/pygobject-2-2.28.6/gobject/gobjectmodule.c was not found in source tree]
#4  0x00007fb8fb6b4fad in ?? ()
#5  0x0000000000000025 in ?? ()
#6  0x00000000023021f0 in ?? ()
#7  0x0000000800000001 in ?? ()
#8  0x0000000002610e00 in ?? ()
#9  0x0000000000000001 in ?? ()
#10 0x0000000000000000 in ?? ()