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Date: Thu, 01 Jun 2006 08:28:03 -0700
From: Brian Dessent <brian AT dessent DOT net>
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Subject: Re: debug information
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Wynfield Henman wrote:

> If anyone would give me a lead as to how to get a more meaningful
> backtrace from gdb, I would appreciate it.

Please search the archives for the many recent threads on this topic. 
What you are seeing is not an actual SIGSEGV, it is a bug/limitation in
gdb related to how Cygwin works internally.  Here is a starting point:

<http://www.google.com/search?num=100&q=site%3Acygwin.com+inurl%3Aml+inurl%3Acygwin+inurl%3A2006+gdb+sigsegv+pthread>

> I was wandering if I have to build a new cygwin.dll (using cygwin)
> with symbol information or it that is even possible.

Debug symbols for the Cygwin DLL are in a separate .dbg file, and you
can just download them from the snapshot page.  However, the real cause
of your problem is that the gdb you are using is too old to contain the
fix to this problem.  
To effectively debug Cygwin apps at the moment requires both a CVS build
of gdb and a recent Cygwin snapshot.  The current release binaries of
both are not sufficient.  In fact the first step of debugging any Cygwin
problem is to use the latest snapshot, as the problem may already be
fixed.

As a workaround you can type "continue" (or just "c") at the gdb prompt
whenever you see one of these spurious SIGSEGVs in any of the pthread_*
functions.  This can get extremely tedious though.

Brian

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