Gilles Arnaud wrote: > Hello, > > I've got a nasty bug and no idea to deal with : > > here is the method :
Big snip. The Python code is unlikely to be your problem. > and the trace > <trace> > in None [(-2.0, 2.0), (-2.0, 2.0)] [0.1385039192456847, > 0.87787941093093491] 2 2 <function undo at 0x81ff94c> > [0.1385039192456847, 0.87787941093093491] That's a very mangled trace! > the first call of the methode succeed > all following call failed. So the first call is leaving a bomb behind. > > I've got different scenario which call this low level methode, > many succeed, some failed this way. > > what's happened ? > If someone got an idea ? > what can raise this exception ? At this stage, without the benefit of look-ahead, one could only blame gamma rays or pointy-eared aliens :-) > > My program is written partially in python and partially in C. > the top level is in python which call a C optimisation routine > which use a callback (PyObject_CallMethod) to evaluate the cost in > python again. Aha! *Now* you tell us. *You* have "denormalised" the stack. Read your C code carefully. Use a debugger, or put some "printf()" in it. With PyObject_CallMethod, do the format descriptors and the arguments match? Are you testing the returned value for NULL and acting accordingly? Is the called-from-C Python method ever executed? Try putting a print statement (that shows the args) at the top. More generally, are you testing the returned value from each and every C API call? Are you testing for the correct error value (some return NULL, some -1, ...)? Are you doing the right thing on error? A catalogue of the different ways of messing things up using C would take forever to write. If you can't find your problem, post the code, either on the newsgroup or as a web page. Hope this helps, John -- http://mail.python.org/mailman/listinfo/python-list
