Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com Date: Mon, 16 Feb 2004 09:49:19 -0500 From: Christopher Faylor To: cygwin@cygwin.com Subject: Re: 20040214 no fix for unzip, cygwin debugging howto? Message-ID: <20040216144919.GE14904@redhat.com> Mail-Followup-To: cygwin@cygwin.com References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.1i X-IsSubscribed: yes Reply-To: cygwin@cygwin.com On Mon, Feb 16, 2004 at 12:09:44AM -0500, Thomas L Roche wrote: >Thomas L Roche Mon, 16 Feb 2004 00:01:10 -0500 >> Unfortunately 20040215 came out while I was debugging 20042014. >> Since you > >do not > >> claim to have done anything that might have actually fixed the >> problem, the results obtained at > >> http://cygwin.com/ml/cygwin/2004-02/msg00705.html > >> are still relevant. What you have discovered is that when memcpy is given a NULL pointer it will case a SEGV. What we need to discover is why the pointer was NULL. When debugging problems like this and you see an error message, try to find out where the error message came from and either set a breakpoint there or, if you can, to save time, work back from that point to see if you can see an obvious point to set a breakpoint where you can determine what caused the NULL. My strace change added additional debugging to try to determine why cmalloc was returning NULL. That's what needs to be debugged, not the fact that cygwin eventually SEGVs. -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/