Fatal Python error: PyEval_RestoreThread: NULL tstate

reinhard rnadrchal at proceryon.at
Thu Sep 11 08:47:12 CEST 2003

Our project was developed with Python 2.0 and includes some Tk 8.3 
extension widgets as well as python extensions using the CXX interface.

After moving to Python 2.3 and TclTk 8.4 our program hangs with the 
following message:

Fatal Python error: PyEval_RestoreThread: NULL tstate

The strange thing is that this happens in a not very predictible way; 
some data is loaded and displayed in a self-made Tk widget. This works 
fine a couple of times and usually crashes when a widget is closed and a 
new one is opend. Debugging the widget code didn't give any hints.

Does anyone know which changes in python (2.0 -> 2.3) or TclTk/tkinter 
(8.3 -> 8.4) might be responsible for this? Are there any solutions?

Reinhard Nadrchal

More information about the Python-list mailing list