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Date: Wed, 14 May 2014 13:08:50 -0400
From: Christopher Faylor <cgf-use-the-mailinglist-please@cygwin.com>
To: cygwin@cygwin.com
Subject: Re: Debugging sub-processes with gdb
Message-ID: <20140514170850.GC6620@ednor.casa.cgf.cx>
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References: <f5boaz0e6qb.fsf@troutbeck.inf.ed.ac.uk> <20140514152505.GB6620@ednor.casa.cgf.cx> <f5bk39oe5ic.fsf@troutbeck.inf.ed.ac.uk>
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On Wed, May 14, 2014 at 04:36:59PM +0100, Henry S. Thompson wrote:
>Christopher Faylor writes:
>> If you have control over the code you could have it print a pid, wait,
>> and then attach to it with gdb.  That works.
>
>Understood, will do.

I should have mentioned, as an alternative approach, if you're willing
to rebuild the Cygwin DLL, you can configure and build it with
--enable-debugging.  Then you can set an environment variable
CYGWIN_DEBUG=xemacs

That will start a gdb sessions every time Cygwin runs a program
with 'xemacs' in its name.

Be advised however that --enable-debugging adds some check to the cygwin
dll which can slow it down noticeably and, in some rare situations,
introduce some races which cause crashes that you wouldn't see with
the non-debugging variant.

cgf

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