1.7.5: cygwin programs throw STATUS_ACCESS_VIOLATION exceptions

[Christopher Faylor]

On Tue, Apr 20, 2010 at 09:19:28AM +0300, Yuval Emek wrote:
>On Mon, Apr 19, 2010 at 20:48, Christopher Faylor wrote:
>> On Mon, Apr 19, 2010 at 10:48:18AM -0400, Larry Hall (Cygwin) wrote:
>>>On 4/19/2010 7:44 AM, Yuval Emek wrote:
>>>> On Mon, Apr 19, 2010 at 09:32, Christopher Faylor
>>>> <cgf-use-the-mailinglist-please...> ?wrote:
>>> ? ?^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>><http://cygwin.com/acronyms/#PCYMTNQREAIYR>. ?Feeding spammers just makes
>>>them hungry.
>>>
>>><snip>
>>>
>>>>> p.envptr is supposed to be filled in by the call to _cygwin_crt0_common
>>>>> in cygwin_attach_dll. ?It is supposed to be set to the address of the
>>>>> "environ" variable in the DLL. ?It is not supposed to be NULL. ?That
>>>>> assignment should actually not even be necessary but the fact that
>>>>> envptr may be NULL is a problem. ?Of course, it could just be some
>>>>> non-NULL garbage too. ?Running in gdb and getting a stack trace would be
>>>>> instructive.
>>>>
>>>> Can you be more specific? (I have been using cygwin for a while, but I
>>>> never debugged it beforehand.)
>>>> I can install gdb using setup.exe . What should I do then in order to
>>>> obtain a stack trace?
>>>
>>>Grab a snapshot from <http://cygwin.com/snapshots/>. ?You want the DLL
>>>and debugging info at least.
>>
>> And, assuming that you can actually run gdb, just "gdb bash" and then "r".
>
>I installed gdb and then downloaded the (latest) snapshots of
>cygwin1.dll and cygwin1.dbg and extracted then to /bin/ (replacing the
>previous cygwin1.dll) .
>Running gdb bash seems to fail since there are no debugging symbols.
>In particular, when typing r in the gdb prompt, I get the following
>output:
>
>Starting program: /usr/bin/bash
>[New thread 3800.0x15b4]
>(no debugging symbols found)
>(no debugging symbols found)
>(no debugging symbols found)
>[New thread 3800.0x13f4]
>
>[1]+  Stopped                 gdb bash
>
>(Makes sense, I guess, as bash was not compiled with debugging info.)
>Can I download debugging info for bash from somewhere? (As far as I
>understand, I don't even have the source code for bash.)
>Is there something else I can do?

I'm not interested in bash symbols.

In the above it sounds like you may actually be running gdb from bash.

I suggested bash because I thought most cygwin programs were dying but,
on rereading the original report, you only mentioned xterm, emacs, and
subversion.  So, the thing to try would be to run gdb on one of those
from a c:\> prompt.  And, it really would be as simple as just typing:

gdb svn
r
bt

and reporting the backtrace.

cgf

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