bug#13653: 24.2.93; cygw32 in daemon mode aborts in response to kill command

bug#13653: 24.2.93; cygw32 in daemon mode aborts in response to kill command

[Ken Brown]

In the cygw32 build, start emacs in daemon mode:

$ emacs --daemon -Q

Now kill it from the terminal:

$ kill PID

The result is an Emacs Abort Dialog box saying a fatal error has 
occurred and asking me if I want to attach a debugger.  I have two 
problems with this.  First, a kill command shouldn't cause emacs to 
abort.  Second, I don't think the cygw32 build should ever pop up an 
abort dialog box.  None of the other emacs builds on Cygwin do this, so 
it's surprising and confusing to users.

In GNU Emacs 24.2.93.1 (i686-pc-cygwin)
  of 2013-02-07 on fiona
Windowing system distributor `Microsoft Corp.', version 0.0.0
Configured using:
  `configure
  '--srcdir=/home/kbrown/src/cygemacs/emacs-24.2.93-1/src/emacs-24.2.93'
  '--prefix=/usr' '--exec-prefix=/usr' '--bindir=/usr/bin'
  '--sbindir=/usr/sbin' '--libexecdir=/usr/lib' '--datadir=/usr/share'
  '--localstatedir=/var' '--sysconfdir=/etc' '--datarootdir=/usr/share'
  '--docdir=/usr/share/doc/emacs' '-C' '--with-w32' 'CC=gcc'
  'CFLAGS=-ggdb -O2 -pipe
 
-fdebug-prefix-map=/home/kbrown/src/cygemacs/emacs-24.2.93-1/build=/usr/src/debug/emacs-24.2.93-1
 
-fdebug-prefix-map=/home/kbrown/src/cygemacs/emacs-24.2.93-1/src/emacs-24.2.93=/usr/src/debug/emacs-24.2.93-1'
  'LDFLAGS=-L/usr/lib/ncursesw' 'LIBS='
  'CPPFLAGS=-I/usr/include/ncursesw''

bug#13653: 24.2.93; cygw32 in daemon mode aborts in response to kill command

[Lars Ingebrigtsen]

Ken Brown <kbrown@cornell.edu> writes:

> In the cygw32 build, start emacs in daemon mode:
>
> $ emacs --daemon -Q
>
> Now kill it from the terminal:
>
> $ kill PID
>
> The result is an Emacs Abort Dialog box saying a fatal error has
> occurred and asking me if I want to attach a debugger.  I have two
> problems with this.  First, a kill command shouldn't cause emacs to
> abort.  Second, I don't think the cygw32 build should ever pop up an
> abort dialog box.  None of the other emacs builds on Cygwin do this,
> so it's surprising and confusing to users.

(This bug report unfortunately got no response at the time.)

Are you still seeing this problem in more recent Emacs versions?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#13653: 24.2.93; cygw32 in daemon mode aborts in response to kill command

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Date: Sun, 06 Dec 2020 20:14:27 +0100
> Cc: 13653@debbugs.gnu.org
> 
> Ken Brown <kbrown@cornell.edu> writes:
> 
> > In the cygw32 build, start emacs in daemon mode:
> >
> > $ emacs --daemon -Q
> >
> > Now kill it from the terminal:
> >
> > $ kill PID
> >
> > The result is an Emacs Abort Dialog box saying a fatal error has
> > occurred and asking me if I want to attach a debugger.  I have two
> > problems with this.  First, a kill command shouldn't cause emacs to
> > abort.  Second, I don't think the cygw32 build should ever pop up an
> > abort dialog box.  None of the other emacs builds on Cygwin do this,
> > so it's surprising and confusing to users.
> 
> (This bug report unfortunately got no response at the time.)
> 
> Are you still seeing this problem in more recent Emacs versions?

Assuming that Ken says this is still an issue: how does 'kill' work in
its Cygwin version?  Specifically, is it possible that it runs the
signal handler in a separate thread, like what Windows does with
SIGINT handlers of console programs if one types Ctrl-C?  If so, I
think I know the reason and can describe the details; fixing that is
not trivial, to say the least.

bug#13653: 24.2.93; cygw32 in daemon mode aborts in response to kill command

[Ken Brown]

On 12/6/2020 2:25 PM, Eli Zaretskii wrote:
>> From: Lars Ingebrigtsen <larsi@gnus.org>
>> Date: Sun, 06 Dec 2020 20:14:27 +0100
>> Cc: 13653@debbugs.gnu.org
>>
>> Ken Brown <kbrown@cornell.edu> writes:
>>
>>> In the cygw32 build, start emacs in daemon mode:
>>>
>>> $ emacs --daemon -Q
>>>
>>> Now kill it from the terminal:
>>>
>>> $ kill PID
>>>
>>> The result is an Emacs Abort Dialog box saying a fatal error has
>>> occurred and asking me if I want to attach a debugger.  I have two
>>> problems with this.  First, a kill command shouldn't cause emacs to
>>> abort.  Second, I don't think the cygw32 build should ever pop up an
>>> abort dialog box.  None of the other emacs builds on Cygwin do this,
>>> so it's surprising and confusing to users.
>>
>> (This bug report unfortunately got no response at the time.)
>>
>> Are you still seeing this problem in more recent Emacs versions?
> 
> Assuming that Ken says this is still an issue: how does 'kill' work in
> its Cygwin version?  Specifically, is it possible that it runs the
> signal handler in a separate thread, like what Windows does with
> SIGINT handlers of console programs if one types Ctrl-C?  If so, I
> think I know the reason and can describe the details; fixing that is
> not trivial, to say the least.

No, it's not an issue anymore.  Closing.

Ken