Subject: bug#50666: closed (Re: bug#50666: 28.0.50; Fix native compilation on Cygwin)

From: [email-masked] (GNU bug Tracking System)
Date: Sun, 31 Oct 2021 23:54:01 +0000

Your bug report

#50666: 28.0.50; Fix native compilation on Cygwin

which was filed against the emacs package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
50666: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=50666
GNU Bug Tracking System
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Subject: Re: bug#50666: 28.0.50; Fix native compilation on Cygwin
From: Ken Brown <[email-masked]>
To: Achim Gratz <[email-masked]>, [email-masked]
Date: Sun, 31 Oct 2021 19:52:56 -0400
List-Id: <debbugs-submit.debbugs.gnu.org>

On 10/31/2021 4:22 PM, Achim Gratz wrote:
> Ken Brown writes:
>> On 10/29/2021 2:02 PM, Eli Zaretskii wrote:
>>>> Thanks for the suggestion.  How's this?
>>> LGTM, thanks.
>>
>> OK, I'll wait a few days before pushing it, in case Achim wants to chime in.
> 
> Go ahead.  While it's somewhat unsatisfatory to drop the ball like this,
> I also don't see it as a good investment of time to get to the bottom of
> the (multiple) issues at play.  The outcome might still be that it
> doesn't quite work even if we'd get there.  If somebody is interested
> enough we'll hear of it I'd think.

I've pushed it and am closing this bug report for now.  We can always revisit it 
later.

Ken

Subject: 28.0.50; Fix native compilation on Cygwin
From: Ken Brown <[email-masked]>
To: [email-masked]
Date: Sat, 18 Sep 2021 16:46:42 -0400
List-Id: <debbugs-submit.debbugs.gnu.org>

Building --with-native-compilation on 32-bit Cygwin currently fails with
errors like the following:

child_info_fork::abort: address space needed by
'simple-fab5b0cf-aaf18a4e.eln' (0x5910000) is already occupied

This happens because shared libraries (usually DLLs, but also *.eln
files in this case) often need to be rebased in order for Cygwin's fork
implementation to work.  See

   https://cygwin.com/cygwin-ug-net/highlights.html#ov-hi-process-problems

for an explanation.  It's mostly an issue in the 32-bit case because of
the limited address space, but on rare occasions it can be a problem on
64-bit Cygwin also.

For shared libraries installed in standard places, Cygwin normally takes
care of the rebasing automatically.  But if libraries are created in the
course of a build and then used later in the build, an "ephemeral" rebase
might be necessary.  This is the case for the *.eln libraries produced
during the emacs build.

In a followup to this message, I'll submit a patch that does this
ephemeral rebase and fixes the build problem.

Note: The build will not actually be convenient to use on 32-bit Cygwin, because 
sooner or later the *.eln files in ~/.emacs.d/eln-cache will also need to be 
rebased.  I hope to address this in future patches.

Ken