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Re: [Xotcl] segmentation faults and bus errors

From: Artur Trzewik <>
Date: Sat, 21 Jul 2007 11:31:41 +0100

> I bring bad news. I am receiving seg faults and bus errors while
> running XOTcl code. I am running XOTcl 1.5.3 and Tcl 8.4 on both
> Linux x86 and OS X PPC. I received the errors randomly on both
> platforms. This started occuring when I reloaded the source code. At
> first I thought it was related to Tcl packaging, but I mostly removed
> calls to package require and package forget. Currently I just use
> source to load most files. I am writing code generation libraries
> and using Object eval so I may be doing new things with XOTcl. How
> should I go about debugging these seg faults? Are core dumps useful?
> I'll try to write a script that reproduces the problem, but I
> haven't really narrowed the problem down yet.
> Any help is much appreciated.
> Thanks,
> Ben
> _______________________________________________
Hello Ben!

I have also very seldom some segmentation faults with Tcl/XOTcl (and
many another extensions).
I have noticed, that it can occurs when I am debugging and changing code
(by using XOTclIDE).
So it is similar to your scenario.
It can occurs by me when I suspend processing of one method (with tkwait
- used internally by debugger)
and from another event handler (beginned from Tk -command) I manipulate
some objects.
The program have problems when I try to fire tkwait variable (resume the
So I suppose you should not reload the package by itself.

The best method to have a bug fix is to write some short script that
always reproduces the error.
I have not a success to write it yet. Even if I try to reproduce the
same debugging session it does not occurs.
Because the error is very seldom it is not possible to fix it without
this script.