GUI application death catcher?

Douglas Alan nessus at
Thu Feb 19 00:29:13 CET 2004

I'm writing a GUI app in Python that will be used on the International
Space Station.  I'd like for the app to be as robust as possible and,
consequently, if it crashes, for there to be a log file written and a
coherent error message displayed to the astronaut.

My original approach to this was to write an in-process handler in
Python that would catch all uncaught exceptions and log the error to a
file and then hand-hold the user.  This turned out to be a bit hairy
because of all the additional possible errors that might happen while
handling the original error, but I made a decent stab at it.
Unfortunately, I find that as I keep working on the program, I often
break the error handler by breaking some utility code that the error
handler uses.  This isn't so good, so it's back to the drawing board a

One approach I might take now is to maintain duplicate utility
libraries -- one for the error handler and one for the rest of the
code.  That way I lessen the risk of breaking the error handler when I
break the rest of the program.  Another approach, which is what I am
leaning towards at the moment, would be to have the error handler be a
completely separate process that monitors the application and takes
over if and when the application fails.  I would like to write this in
Python, of course, but then I have the worry of what happens if the
Python installation gets bit rot, or something, and the monitoring
program consequently won't run properly.  So, now I'm thinking that a
completely stand-alone, statically linked executable would be best for
this particular task.

But I'm really not in the mood at the moment to write a Windows C++
GUI app.  (Oh, did I mention that unfortunately this is going to run
on a Windows 2000 machine?)  I'm figuring that such programs must
already exist, since there must be a lot of demand for them.  In fact,
it seems that when using Windows, I often see pop-up dialogs about how
some program or another crashed and would I like to send a report off
to M$?  I'd like the same thing for my app, only for it to send a
report off to me, rather than M$.  Does anyone know of a preexisting
(preferably freeware) utility that does what I want?


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