bug#22174: 24.4; emacs --daemon crashes when ssh is disconnected. I am using lucid x toolkit.

bug#22174: 24.4; emacs --daemon crashes when ssh is disconnected. I am using lucid x toolkit.

[Cody Addison]

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I am using emacs in server mode on a remote machine. The intent is to
have a persistent emacs session that I can reconnect to.

Here are the steps I typically do:
% ssh <machine>
% tmux attach (This step doesn't seem important. I've tried this with and
without tmux).
% emacs --daemon
% emacsclient -n -c
% tmux detach
% exit

At this point the server is toast.

I am using cygwin on Windows 7 for the ssh client and X server. I have
also tried emacs 24.5 with no success. I have tried multiple X tool kits
(athena and motif) with no success.




In GNU Emacs 24.4.1 (x86_64-unknown-linux-gnu, X toolkit, Xaw scroll bars)
 of 2015-10-01 on sdocg001
Windowing system distributor `The Cygwin/X Project', version 11.0.11704000
System Description: Ubuntu 14.04.1 LTS

Configured using:
 `configure --with-x-toolkit=lucid
 --prefix=/home/a0866938/opt/emacs-24.4 --with-jpeg=no --with-gif=no
 --with-tiff=no'

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  show-paren-mode: t
  tooltip-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
M-x r e p o <tab> r t <tab> <return>

Recent messages:
Loading delsel...done
Loading paren...done
Loading /home/a0866938/emacs_scripts/tiasm_mode.el (source)...done
Loading
/home/a0866938/.emacs.d/elpa/color-theme-20080305.34/themes/color-theme-example.el
(source)...done
Loading
/home/a0866938/.emacs.d/elpa/color-theme-20080305.34/themes/color-theme-example.elc...done
Loading
/home/a0866938/.emacs.d/elpa/color-theme-20080305.34/themes/color-theme-library.el
(source)...done
Loading
/home/a0866938/.emacs.d/elpa/color-theme-20080305.34/themes/color-theme-library.elc...done
For information about GNU Emacs and the GNU system, type C-h C-a.
Making completion list...

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev
gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util
help-fns mail-prsvr mail-utils help-mode solarized-theme
solarized-definitions cl-macs color-theme wid-edit cl gv cl-loaddefs
cl-lib jka-compr paren delsel cus-start cus-load color-theme-autoloads
info easymenu package epg-config time-date tooltip electric uniquify
ediff-hook vc-hooks lisp-float-type mwheel x-win x-dnd tool-bar dnd
fontset image regexp-opt fringe tabulated-list newcomment lisp-mode
prog-mode register page menu-bar rfn-eshadow timer select scroll-bar
mouse jit-lock font-lock syntax facemenu font-core frame cham georgian
utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese case-table epa-hook jka-cmpr-hook help simple abbrev
minibuffer nadvice loaddefs button faces cus-face macroexp files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote make-network-process
dbusbind gfilenotify dynamic-setting x-toolkit x multi-tty emacs)

Memory information:
((conses 16 277417 13086)
 (symbols 48 24532 0)
 (miscs 40 40 109)
 (strings 32 43033 16146)
 (string-bytes 1 860921)
 (vectors 16 14072)
 (vector-slots 8 432696 5323)
 (floats 8 174 265)
 (intervals 56 220 210)
 (buffers 960 12)
 (heap 1024 41052 1153))

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bug#22174: 24.4; emacs --daemon crashes when ssh is disconnected. I am using lucid x toolkit.

[Eli Zaretskii]

> Date: Mon, 14 Dec 2015 22:05:54 -0600
> From: Cody Addison <cody.addison@gmail.com>
> 
> Here are the steps I typically do:
> % ssh <machine>
> % tmux attach (This step doesn't seem important. I've tried this with and
> without tmux).
> % emacs --daemon
> % emacsclient -n -c
> % tmux detach
> % exit
> 
> At this point the server is toast.

Can you attach GDB to the daemon before the final step, and when it
crashes (or exits or aborts or whatever), produce a backtrace and post
it here?

One more thing to try is the latest emacs-25 branch, if you can build
it or get a hold of snapshot binaries somewhere.

Thanks.

bug#22174: 24.4; emacs --daemon crashes when ssh is disconnected. I am using lucid x toolkit.

[Cody Addison]

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Eli,

Sure. I'll give it a try tonight and send you the results. A few more
details that may help:

1. The exit command hangs. I typically have to use Ctrl-C. This only
happens if I've opened emacsclient with X forwarding. I suspect the server
still has an open connection over ssh, but this isn't really an area I know
much about.
2. I exit the emacs client with C-x C-c. Sometimes I just put the laptop to
sleep without closing emacs or the terminal. Both have the same results.
3. This was working for a while. I don't believe anything has changed since
it stopped working, but it's possible. Right now I can reproduce the crash
every time.

On Tue, Dec 15, 2015 at 9:48 AM, Eli Zaretskii <eliz@gnu.org> wrote:

> > Date: Mon, 14 Dec 2015 22:05:54 -0600
> > From: Cody Addison <cody.addison@gmail.com>
> >
> > Here are the steps I typically do:
> > % ssh <machine>
> > % tmux attach (This step doesn't seem important. I've tried this with and
> > without tmux).
> > % emacs --daemon
> > % emacsclient -n -c
> > % tmux detach
> > % exit
> >
> > At this point the server is toast.
>
> Can you attach GDB to the daemon before the final step, and when it
> crashes (or exits or aborts or whatever), produce a backtrace and post
> it here?
>
> One more thing to try is the latest emacs-25 branch, if you can build
> it or get a hold of snapshot binaries somewhere.
>
> Thanks.
>

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bug#22174: 24.4; emacs --daemon crashes when ssh is disconnected. I am using lucid x toolkit.

[Eli Zaretskii]

[Please keep the bug address on the CC list.]

> Date: Wed, 16 Dec 2015 12:59:49 -0600
> From: Cody Addison <cody.addison@gmail.com>
> 
> Here is the result. I am including the backtrace of all 3 threads. The SIGTERM
> comes when I Ctrl-C the ssh command. I didn't expect that to pass through to
> the emacs daemon.
> 
> (gdb) continue
> Continuing.
> [New Thread 0x7f789b17d700 (LWP 52670)]
> [New Thread 0x7f789a97c700 (LWP 52765)]
> 
> Program received signal SIGTERM, Terminated.
> [Switching to Thread 0x7f789b17d700 (LWP 52670)]
> 
> backtrace thread 1:
> 
> (gdb) thread 1
> [Switching to thread 1 (Thread 0x7f78a10fa880 (LWP 26190))]
> #0 0x00007f789e045e79 in __pselect (nfds=6, readfds=0x7fff4c537f40,
> writefds=0x7fff4c537fc0, exceptfds=0x0, timeout=<optimized out>,
> sigmask=<optimized out>) at ../sysdeps/unix/sysv/linux/pselect.c:77
> 77 ../sysdeps/unix/sysv/linux/pselect.c: No such file or directory.
> (gdb) backtrace
> #0 0x00007f789e045e79 in __pselect (nfds=6, readfds=0x7fff4c537f40,
> writefds=0x7fff4c537fc0, exceptfds=0x0, timeout=<optimized out>,
> sigmask=<optimized out>) at ../sysdeps/unix/sysv/linux/pselect.c:77
> #1 0x000000000065505b in xg_select (fds_lim=6, rfds=0x7fff4c538550,
> wfds=0x7fff4c5385d0, efds=0x0, timeout=0x7fff4c538530, sigmask=0x0)
> at ../../emacs-24.4/src/xgselect.c:105
> #2 0x000000000061b0c7 in wait_reading_process_output (time_limit=0, nsecs=0,
> read_kbd=-1, do_display=true, wait_for_cell=12752882, wait_proc=0x0,
> just_wait_proc=0) at ../../emacs-24.4/src/process.c:4606
> #3 0x000000000053c869 in kbd_buffer_get_event (kbp=0x7fff4c5388b8,
> used_mouse_menu=0x7fff4c538de9, end_time=0x0)
> at ../../emacs-24.4/src/keyboard.c:3906
> #4 0x00000000005390da in read_event_from_main_queue (end_time=0x0,
> local_getcjmp=0x7fff4c538bf0, used_mouse_menu=0x7fff4c538de9)
> at ../../emacs-24.4/src/keyboard.c:2246
> #5 0x000000000053933e in read_decoded_event_from_main_queue (end_time=0x0,
> local_getcjmp=0x7fff4c538bf0, prev_event=12752882,
> used_mouse_menu=0x7fff4c538de9) at ../../emacs-24.4/src/keyboard.c:2309
> #6 0x000000000053a835 in read_char (commandflag=1, map=36984518,
> prev_event=12752882, used_mouse_menu=0x7fff4c538de9, end_time=0x0)
> at ../../emacs-24.4/src/keyboard.c:2895
> #7 0x0000000000546170 in read_key_sequence (keybuf=0x7fff4c538fd0,
> bufsize=30, prompt=12752882, dont_downcase_last=false,
> can_return_switch_frame=true, fix_current_buffer=true,
> prevent_redisplay=false) at ../../emacs-24.4/src/keyboard.c:9088
> #8 0x00000000005375c1 in command_loop_1 ()
> at ../../emacs-24.4/src/keyboard.c:1452
> #9 0x00000000005c970b in internal_condition_case (
> bfun=0x5371f9 <command_loop_1>, handlers=12804482,
> hfun=0x536ae8 <cmd_error>) at ../../emacs-24.4/src/eval.c:1348
> #10 0x0000000000536f53 in command_loop_2 (ignore=12752882)
> at ../../emacs-24.4/src/keyboard.c:1177
> #11 0x00000000005c8f1d in internal_catch (tag=12800418,
> func=0x536f2d <command_loop_2>, arg=12752882)
> at ../../emacs-24.4/src/eval.c:1112
> #12 0x0000000000536f01 in command_loop ()
> at ../../emacs-24.4/src/keyboard.c:1156
> #13 0x00000000005366e3 in recursive_edit_1 ()
> at ../../emacs-24.4/src/keyboard.c:777
> #14 0x0000000000536850 in Frecursive_edit ()
> at ../../emacs-24.4/src/keyboard.c:848
> #15 0x0000000000534867 in main (argc=2, argv=0x7fff4c5393d8)
> at ../../emacs-24.4/src/emacs.c:1646
> 
> backtrace thread 2:
> 
> (gdb) thread 2
> [Switching to thread 2 (Thread 0x7f789c1a5700 (LWP 26191))]
> #0 0x00007f789e04112d in poll () at ../sysdeps/unix/syscall-template.S:81
> 81 ../sysdeps/unix/syscall-template.S: No such file or directory.
> (gdb) backtrace
> #0 0x00007f789e04112d in poll () at ../sysdeps/unix/syscall-template.S:81
> #1 0x00007f789e57ffe4 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
> #2 0x00007f789e5800ec in g_main_context_iteration ()
> from /lib/x86_64-linux-gnu/libglib-2.0.so.0
> #3 0x00007f789e580129 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
> #4 0x00007f789e5a4f05 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
> #5 0x00007f789e321182 in start_thread (arg=0x7f789c1a5700)
> at pthread_create.c:312
> #6 0x00007f789e04e47d in clone ()
> at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111
> 
> backtrace thread 3:
> 
> 0x00007f789e32920b in raise (sig=15)
> at ../nptl/sysdeps/unix/sysv/linux/pt-raise.c:37
> 37 ../nptl/sysdeps/unix/sysv/linux/pt-raise.c: No such file or directory.
> (gdb) backtrace
> #0 0x00007f789e32920b in raise (sig=15)
> at ../nptl/sysdeps/unix/sysv/linux/pt-raise.c:37
> #1 0x00007f789ced5adc in ffi_call_unix64 ()
> from /usr/lib/x86_64-linux-gnu/libffi.so.6
> #2 0x00007f789ced540c in ffi_call ()
> from /usr/lib/x86_64-linux-gnu/libffi.so.6
> #3 0x00007f789e850055 in g_cclosure_marshal_generic_va ()
> from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
> #4 0x00007f789e84f5e7 in ?? ()
> from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
> #5 0x00007f789e868088 in g_signal_emit_valist ()
> from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
> #6 0x00007f789e868ce2 in g_signal_emit ()
> from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
> #7 0x00007f789eb539d5 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
> #8 0x00007f789e57fce5 in g_main_context_dispatch ()
> from /lib/x86_64-linux-gnu/libglib-2.0.so.0
> #9 0x00007f789e580048 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
> #10 0x00007f789e5800ec in g_main_context_iteration ()
> from /lib/x86_64-linux-gnu/libglib-2.0.so.0
> #11 0x00007f789b1851ad in ?? ()
> from /usr/lib/x86_64-linux-gnu/gio/modules/libdconfsettings.so
> #12 0x00007f789e5a4f05 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
> #13 0x00007f789e321182 in start_thread (arg=0x7f789b17d700)
> at pthread_create.c:312
> #14 0x00007f789e04e47d in clone ()
> at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Looks like thread 3, which runs some Glib code, deliberately killed
the entire process by raising SIGTERM.

bug#22174: 24.4; emacs --daemon crashes when ssh is disconnected. I am using lucid x toolkit.

[Eli Zaretskii]

> Date: Wed, 16 Dec 2015 12:59:49 -0600
> From: Cody Addison <cody.addison@gmail.com>
> 
> Here is the result. I am including the backtrace of all 3 threads. The SIGTERM
> comes when I Ctrl-C the ssh command. I didn't expect that to pass through to
> the emacs daemon.

And why do you use Ctrl-C to interrupt ssh?

bug#22174: 24.4; emacs --daemon crashes when ssh is disconnected. I am using lucid x toolkit.

[Eli Zaretskii]

[Please don't omit the bug address from the CC list.]

> Date: Wed, 16 Dec 2015 13:46:09 -0600
> From: Cody Addison <cody.addison@gmail.com>
> 
> Because it hangs. If I start ssh and don't open an emacsclient, exit works
> fine. However, if I start an emacsclient, exit hangs.

How do you exit?  What do you type to exit?

bug#22174: 24.4; emacs --daemon crashes when ssh is disconnected. I am using lucid x toolkit.

[Eli Zaretskii]

[Resending to the bug address.]

> Date: Wed, 16 Dec 2015 13:48:07 -0600
> From: Cody Addison <cody.addison@gmail.com>
> 
> I'm still trying out a few things, but it seems that if I start emacs --daemon
> with DISPLAY unset, things seem to work fine. 

Thanks.

bug#22174: 24.4; emacs --daemon crashes when ssh is disconnected. I am using lucid x toolkit.

[Cody Addison]

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I just type exit. I have also tried logout.

On Wed, Dec 16, 2015 at 2:02 PM, Eli Zaretskii <eliz@gnu.org> wrote:

> [Resending to the bug address.]
>
> > Date: Wed, 16 Dec 2015 13:48:07 -0600
> > From: Cody Addison <cody.addison@gmail.com>
> >
> > I'm still trying out a few things, but it seems that if I start emacs
> --daemon
> > with DISPLAY unset, things seem to work fine.
>
> Thanks.
>

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bug#22174: 24.4; emacs --daemon crashes when ssh is disconnected. I am using lucid x toolkit.

[Eli Zaretskii]

> Date: Wed, 16 Dec 2015 14:04:07 -0600
> From: Cody Addison <cody.addison@gmail.com>
> Cc: 22174@debbugs.gnu.org
> 
> I just type exit. I have also tried logout.

To the shell, after you already exited emacsclient frame?

bug#22174: 24.4; emacs --daemon crashes when ssh is disconnected. I am using lucid x toolkit.

[Cody Addison]

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Yes
On Dec 16, 2015 2:40 PM, "Eli Zaretskii" <eliz@gnu.org> wrote:

> > Date: Wed, 16 Dec 2015 14:04:07 -0600
> > From: Cody Addison <cody.addison@gmail.com>
> > Cc: 22174@debbugs.gnu.org
> >
> > I just type exit. I have also tried logout.
>
> To the shell, after you already exited emacsclient frame?
>

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