git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Uwe Brauer]

Hi

I compiled the above version yesterday. It freezes and crashes 
frequently in when using gnus, without any bug-trace left. What 
can I do to achieve a better bug report?

Uwe Brauer 

Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Eli Zaretskii]

> From: Uwe Brauer <oub@mat.ucm.es>
> Date: Sat, 28 Apr 2018 11:06:34 +0200
> 
> I compiled the above version yesterday. It freezes and crashes 
> frequently in when using gnus, without any bug-trace left. What 
> can I do to achieve a better bug report?

Run Emacs under GDB, and when it crashes type:

  thread apply all bt

Then include the output of the above command in your bug report,
submitted via "M-x report-emacs-bug RET".

Thanks.

Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Uwe Brauer]

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>>> "Eli" == Eli Zaretskii <eliz@gnu.org> writes:

   >> From: Uwe Brauer <oub@mat.ucm.es>
   >> Date: Sat, 28 Apr 2018 11:06:34 +0200
   >> 
   >> I compiled the above version yesterday. It freezes and crashes 
   >> frequently in when using gnus, without any bug-trace left. What 
   >> can I do to achieve a better bug report?

   > Run Emacs under GDB, and when it crashes type:

Thanks, but sorry for my ignorance. What do you mean by
«Run Emacs under GDB»

I googled, could not find am explanation of what that means.

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Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Eli Zaretskii]

> From: Uwe Brauer <oub@mat.ucm.es>
> Date: Sat, 28 Apr 2018 12:11:58 +0200
> 
>    > Run Emacs under GDB, and when it crashes type:
> 
> Thanks, but sorry for my ignorance. What do you mean by
> «Run Emacs under GDB»

Basically, start GDB with Emacs as the executable to debug, then run
Emacs from GDB's command line.

> I googled, could not find am explanation of what that means.

No need to google, the answer is under your fingertips: see the
beginning of the file etc/DEBUG in the Emacs source tree.

Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Uwe Brauer]

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   > Basically, start GDB with Emacs as the executable to debug, then run
   > Emacs from GDB's command line.


Oh well,

I tried gdb /opt/emacs27/bin/emacs
and I obtained
Reading symbols from /opt/emacs27/bin/emacs...(no debugging symbols
found)...done.

But no emacs started.

The message indicates that I should recompile emacs?

   > No need to google, the answer is under your fingertips: see the
   > beginning of the file etc/DEBUG in the Emacs source tree.

Thanks, but just read it, but it is a bit confusing, since it is not
clear to me whether I could start emacs first and then start gdb within
emacs.

So it comes down to this: is 

gdb /opt/emacs27/bin/emacs

in the emacs/src directory the right command to use?
I tried it but emacs does not start, what do I miss?


So shall I recompile emacs with debug options like

  CFLAGS='-O0 -g3' ./configure --enable-checking='yes,glyphs' --enable-check-lisp-object-type

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Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Eli Zaretskii]

> From: Uwe Brauer <oub@mat.ucm.es>
> Cc: Uwe Brauer <oub@mat.ucm.es>, emacs-devel@gnu.org
> Date: Sat, 28 Apr 2018 13:56:28 +0200
> 
>    > Basically, start GDB with Emacs as the executable to debug, then run
>    > Emacs from GDB's command line.
> 
> 
> Oh well,
> 
> I tried gdb /opt/emacs27/bin/emacs
> and I obtained
> Reading symbols from /opt/emacs27/bin/emacs...(no debugging symbols
> found)...done.

Your Emacs was not built with debugging symbols.  The "Preliminaries"
section of etc/DEBUG explains how to build with debugging symbols.

> But no emacs started.

Because you didn't start it.  The GDB "run" command starts the
executable.  This is again described in etc/DEBUG.

> The message indicates that I should recompile emacs?

Yes.

>    > No need to google, the answer is under your fingertips: see the
>    > beginning of the file etc/DEBUG in the Emacs source tree.
> 
> Thanks, but just read it, but it is a bit confusing, since it is not
> clear to me whether I could start emacs first and then start gdb within
> emacs.

You can either start GDB from (another session of) Emacs, or start GDB
from the shell prompt.  In both cases, you should then start Emacs
from GDB.

> So shall I recompile emacs with debug options like
> 
>   CFLAGS='-O0 -g3' ./configure --enable-checking='yes,glyphs' --enable-check-lisp-object-type

Yes, that's a good beginning.

Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Uwe Brauer]

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>>> "Eli" == Eli Zaretskii <eliz@gnu.org> writes:
   >> 
   >> CFLAGS='-O0 -g3' ./configure --enable-checking='yes,glyphs' --enable-check-lisp-object-type

   > Yes, that's a good beginning.

This dos not work. That description most likely is incomplete.

On the prompt that line gives error, so I presume that  CFLAGS='-O0 -g3'
is a setting either in bash or tcsh shell.

Can you please tell me precisely how this setting should work, and may I
recommend change it in the documentation. Once I have finished
successfully the compilation and the debugging I don't mind doing that.

It might be that for experts like you these things are obvious, for a
C debugging beginner like me, they are not.

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Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Eli Zaretskii]

On April 29, 2018 11:46:42 AM GMT+03:00, Uwe Brauer <oub@mat.ucm.es> wrote:
> >>> "Eli" == Eli Zaretskii <eliz@gnu.org> writes:
>    >> 
> >> CFLAGS='-O0 -g3' ./configure --enable-checking='yes,glyphs'
> --enable-check-lisp-object-type
> 
>    > Yes, that's a good beginning.
> 
> This dos not work. That description most likely is incomplete.
> 
> On the prompt that line gives error, so I presume that  CFLAGS='-O0
> -g3'
> is a setting either in bash or tcsh shell.
> 
> Can you please tell me precisely how this setting should work, and may
> I
> recommend change it in the documentation. Once I have finished
> successfully the compilation and the debugging I don't mind doing
> that.
> 
> It might be that for experts like you these things are obvious, for a
> C debugging beginner like me, they are not.

Please show the error message you got.  I just tried the command from
DEBUG to be sure, and it worked for me.

You should type literally the command as written in DEBUG.

Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Uwe Brauer]

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>>> "Eli" == Eli Zaretskii <eliz@gnu.org> writes:

   > On April 29, 2018 11:46:42 AM GMT+03:00, Uwe Brauer <oub@mat.ucm.es> wrote:
   >> >>> "Eli" == Eli Zaretskii <eliz@gnu.org> writes:
   >> >> 
   >> >> CFLAGS='-O0 -g3' ./configure --enable-checking='yes,glyphs'
   >> --enable-check-lisp-object-type
   >> 
   >> > Yes, that's a good beginning.
   >> 
   >> This dos not work. That description most likely is incomplete.
   >> 
   >> On the prompt that line gives error, so I presume that  CFLAGS='-O0
   >> -g3'
   >> is a setting either in bash or tcsh shell.
   >> 
   >> Can you please tell me precisely how this setting should work, and may
   >> I
   >> recommend change it in the documentation. Once I have finished
   >> successfully the compilation and the debugging I don't mind doing
   >> that.
   >> 
   >> It might be that for experts like you these things are obvious, for a
   >> C debugging beginner like me, they are not.

   > Please show the error message you got.  I just tried the command from
   > DEBUG to be sure, and it worked for me.


I restarted my laptop and then

Just typed (using tcsh shell)
 ./configure CFLAGS='-O0 -g3' --enable-checking='yes,glyphs' --enable-check-lisp-object-type --prefix=/opt/emacs27 --wi
th-x-toolkit=athena --with-mailutils


And that worked.

I could compile emacs succesfully. So maybe I owe you an apology. But
think if I am correct that should be written in src/DEBUG:

The line reads

  CFLAGS='-O0 -g3' ./configure --enable-checking='yes,glyphs' --enable-check-lisp-object-type

When I run it I obtain

CFLAGS=-O0 -g3: Command not found.

Which is to expected.  

So it  should be

 ./configure CFLAGS='-O0 -g3' --enable-checking='yes,glyphs' --enable-check-lisp-object-type 

   > You should type literally the command as written in DEBUG.

Not for me. Ok I just checked it seems to work for the bash shell. In
that case still a correction should be in place. Don't you think so.


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Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Uwe Brauer]

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   > Your Emacs was not built with debugging symbols.  The "Preliminaries"
   > section of etc/DEBUG explains how to build with debugging symbols.


   > Because you didn't start it.  The GDB "run" command starts the
   > executable.  This is again described in etc/DEBUG.

It seems that I compiled now the error checking enabled emacs. BTW I
just found out that even for the vanilla compiled emacs there is bug
trace file in /tmp, however its around 300 Mega, so basically worse less
so I continue to give the error enabled emacs a try.

But I still don't get it to work. I do

 cd src/emacs/src (dir where the new emacs is compiled)
 gdb
 run /home/oub/src/emacs/src/emacs

un /home/oub/src/emacs/src/emacs
Starting program:  /home/oub/src/emacs/src/emacs
No executable file specified.Use the "file" or "exec-file" command.

exec-file /home/oub/src/emacs/src/emacs

And nothing happens.

What do I miss?
 

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Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Eli Zaretskii]

> From: Uwe Brauer <oub@mat.ucm.es>
> Cc: Uwe Brauer <oub@mat.ucm.es>, emacs-devel@gnu.org
> Date: Sun, 29 Apr 2018 16:54:03 +0200
> 
> I restarted my laptop and then
> 
> Just typed (using tcsh shell)
>  ./configure CFLAGS='-O0 -g3' --enable-checking='yes,glyphs' --enable-check-lisp-object-type --prefix=/opt/emacs27 --wi
> th-x-toolkit=athena --with-mailutils
> 
> 
> And that worked.
> 
> I could compile emacs succesfully. So maybe I owe you an apology. But
> think if I am correct that should be written in src/DEBUG:
> 
> The line reads
> 
>   CFLAGS='-O0 -g3' ./configure --enable-checking='yes,glyphs' --enable-check-lisp-object-type
> 
> When I run it I obtain
> 
> CFLAGS=-O0 -g3: Command not found.

Maybe this is something specific to tcsh.  The command is written for
Bourne-shell compatible shells, AFAIU.

>    > You should type literally the command as written in DEBUG.
> 
> Not for me. Ok I just checked it seems to work for the bash shell. In
> that case still a correction should be in place. Don't you think so.

I'm not sure the script will work for non-Bourne shells, but I'm not
an expert on that.

Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Noam Postavsky]

On 29 April 2018 at 11:09, Eli Zaretskii <eliz@gnu.org> wrote:

>>   CFLAGS='-O0 -g3' ./configure --enable-checking='yes,glyphs' --enable-check-lisp-object-type
>>
>> When I run it I obtain
>>
>> CFLAGS=-O0 -g3: Command not found.
>
> Maybe this is something specific to tcsh.  The command is written for
> Bourne-shell compatible shells, AFAIU.

It would make sense to change etc/DEBUG as Uwe suggests here anyway:
the autoconf manual recommends setting variables (apart from
CONFIG_SHELL) in the ./configure command line rather than the
environment.

https://www.gnu.org/software/autoconf/manual/autoconf-2.65/html_node/Defining-Variables.html

> I'm not sure the script will work for non-Bourne shells, but I'm not
> an expert on that.

The configure script has #!/bin/sh at the top, so the script itself
won't be evaluated by tcsh (unless you do 'tcsh ./configure ...'
(which fails immediately)).

Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Noam Postavsky]

On 29 April 2018 at 11:01, Uwe Brauer <oub@mat.ucm.es> wrote:

> But I still don't get it to work. I do
>
>  cd src/emacs/src (dir where the new emacs is compiled)
>  gdb
>  run /home/oub/src/emacs/src/emacs

> What do I miss?

It should be

cd src/emacs/src
gdb emacs
run

Although if you follow etc/DEBUG, you would be running gdb from within
Emacs using M-x gdb.

Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Paul Eggert]

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Noam Postavsky wrote:
> the autoconf manual recommends setting variables (apart from
> CONFIG_SHELL) in the ./configure command line rather than the
> environment.

Quite right, and the Emacs doc mostly follows that advice, but there were a few 
cases where it still used the older convention of setting CFLAGS in the 
environment. I fixed the cases I found by installing the attached into master.

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From bf12cc6c7830937b4c1a3df46294e74bea749a5f Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Sun, 29 Apr 2018 09:28:11 -0700
Subject: [PATCH] Advise CFLAGS= operand, not in environment, when configuring

---
 etc/DEBUG    | 3 ++-
 etc/PROBLEMS | 2 +-
 nt/INSTALL   | 6 ++++--
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/etc/DEBUG b/etc/DEBUG
index a779295..49764fc 100644
--- a/etc/DEBUG
+++ b/etc/DEBUG
@@ -16,7 +16,8 @@ make the debugging easier.  Here's the configure-time options we
 recommend (they are in addition to any other options you might need,
 such as --prefix):
 
-  CFLAGS='-O0 -g3' ./configure --enable-checking='yes,glyphs' --enable-check-lisp-object-type
+  ./configure --enable-checking='yes,glyphs' --enable-check-lisp-object-type \
+    CFLAGS='-O0 -g3'
 
 The CFLAGS value is important: debugging optimized code can be very
 hard.  (If the problem only happens with optimized code, you may need
diff --git a/etc/PROBLEMS b/etc/PROBLEMS
index d19efaa..8fb3d74 100644
--- a/etc/PROBLEMS
+++ b/etc/PROBLEMS
@@ -126,7 +126,7 @@ This version of GCC is buggy: see
 You can work around this error in gcc-4.5 by omitting sibling call
 optimization.  To do this, configure Emacs with
 
- CFLAGS="-g -O2 -fno-optimize-sibling-calls" ./configure
+ ./configure CFLAGS="-g -O2 -fno-optimize-sibling-calls"
 
 ** Emacs compiled with GCC 4.6.1 crashes on MS-Windows when C-g is pressed
 
diff --git a/nt/INSTALL b/nt/INSTALL
index d2e5e99..6706942 100644
--- a/nt/INSTALL
+++ b/nt/INSTALL
@@ -52,7 +52,8 @@ build will run on Windows 9X and newer systems).
      You can pass other options to the configure script.  Here's a
      typical example (for an in-place debug build):
 
-       CFLAGS='-O0 -g3' ./configure --prefix=/d/usr/emacs --enable-checking='yes,glyphs'
+       ./configure --prefix=/d/usr/emacs --enable-checking='yes,glyphs' \
+         CFLAGS='-O0 -g3'
 
   3. After the configure script finishes, it should display the
      resulting configuration.  After that, type
@@ -461,7 +462,8 @@ build will run on Windows 9X and newer systems).
   A few frequently used options are needed when you want to produce an
   unoptimized binary with runtime checks enabled:
 
-     CFLAGS='-O0 -g3' ./configure --prefix=PREFIX --enable-checking='yes,glyphs'
+     ./configure --prefix=PREFIX --enable-checking='yes,glyphs' \
+       CFLAGS='-O0 -g3'
 
   Once invoked, the configure script will run for some time, and, if
   successful, will eventually produce a summary of the configuration
-- 
2.7.4

Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Eli Zaretskii]

> From: Noam Postavsky <npostavs@gmail.com>
> Date: Sun, 29 Apr 2018 11:26:29 -0400
> Cc: Uwe Brauer <oub@mat.ucm.es>, Emacs developers <emacs-devel@gnu.org>
> 
> It would make sense to change etc/DEBUG as Uwe suggests here anyway:
> the autoconf manual recommends setting variables (apart from
> CONFIG_SHELL) in the ./configure command line rather than the
> environment.

Fine with me, feel free (on the release branch, please).

> > I'm not sure the script will work for non-Bourne shells, but I'm not
> > an expert on that.
> 
> The configure script has #!/bin/sh at the top

Granted I knew that.  But I stopped using tcsh 20 years ago, so I
don't feel confident having any intelligent discourse about its
quirks.

Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Eli Zaretskii]

> From: Noam Postavsky <npostavs@gmail.com>
> Date: Sun, 29 Apr 2018 11:33:01 -0400
> 
> cd src/emacs/src
> gdb emacs

I suggest

  gdb ./emacs

to be sure you run the correct executable.

> Although if you follow etc/DEBUG, you would be running gdb from within
> Emacs using M-x gdb.

Right.

Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Uwe Brauer]

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>>> "Noam" == Noam Postavsky <npostavs@gmail.com> writes:

   > On 29 April 2018 at 11:01, Uwe Brauer <oub@mat.ucm.es> wrote:
   >> But I still don't get it to work. I do
   >> 
   >> cd src/emacs/src (dir where the new emacs is compiled)
   >> gdb
   >> run /home/oub/src/emacs/src/emacs

   >> What do I miss?

   > It should be

   > cd src/emacs/src
   > gdb emacs
   > run

That it was, thanks!! May I suggest, again, to add just these lines to
the DEBUG file. Most likely this all trivial stuff for you but I found
it somehow difficult to deduce.


   > Although if you follow etc/DEBUG, you would be running gdb from within
   > Emacs using M-x gdb.



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Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Uwe Brauer]

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>>> "Eli" == Eli Zaretskii <eliz@gnu.org> writes:

   >> From: Noam Postavsky <npostavs@gmail.com>
   >> Date: Sun, 29 Apr 2018 11:33:01 -0400
   >> 
   >> cd src/emacs/src
   >> gdb emacs

   > I suggest

   >   gdb ./emacs

   > to be sure you run the correct executable.

Yes of course!
   >> Although if you follow etc/DEBUG, you would be running gdb from within
   >> Emacs using M-x gdb.

   > Right.



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Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Eli Zaretskii]

> Cc: Uwe Brauer <oub@mat.ucm.es>, Emacs developers <emacs-devel@gnu.org>
> From: Paul Eggert <eggert@cs.ucla.edu>
> Date: Sun, 29 Apr 2018 09:30:58 -0700
> 
> I fixed the cases I found by installing the attached into master.

Thanks, but please backport to the release branch as well.

> +  ./configure --enable-checking='yes,glyphs' --enable-check-lisp-object-type \
> +    CFLAGS='-O0 -g3'

Please use one long line, to avoid problems when people naïvely
copy/paste the command into the shell prompt.

>    A few frequently used options are needed when you want to produce an
>    unoptimized binary with runtime checks enabled:
>  
> -     CFLAGS='-O0 -g3' ./configure --prefix=PREFIX --enable-checking='yes,glyphs'
> +     ./configure --prefix=PREFIX --enable-checking='yes,glyphs' \
> +       CFLAGS='-O0 -g3'

Likewise here.

Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Eli Zaretskii]

> From: Uwe Brauer <oub@mat.ucm.es>
> Date: Sun, 29 Apr 2018 18:39:20 +0200
> 
> That it was, thanks!! May I suggest, again, to add just these lines to
> the DEBUG file.

You don't know me very well, do you?  Already done.

Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Paul Eggert]

Eli Zaretskii wrote:
> Please use one long line, to avoid problems when people naïvely
> copy/paste the command into the shell prompt.

Users can copy-paste the first example as-is already, since the earlier line 
ends in backslash. (The second example can't be copy-pasted as-is because of the 
metavariable, though the backslash doesn't hurt.)

If we're talking about truly naive users, then these commands are too long 
anyway. Is there some way we can shorten the commands to make them less 
error-prone? Maybe use shell scripts and tell users to run 'build-aux/thing1' 
and 'build-aux/thing2', that sort of thing?

I'll hold off backporting until we get the important matter of backslashes 
resolved. :-)

Re: git+master: c6e6503900534d939dd94b812563c27f22c49b7d crash when using gnus

[Eli Zaretskii]

> Cc: npostavs@gmail.com, oub@mat.ucm.es, emacs-devel@gnu.org
> From: Paul Eggert <eggert@cs.ucla.edu>
> Date: Sun, 29 Apr 2018 10:18:59 -0700
> 
> Eli Zaretskii wrote:
> > Please use one long line, to avoid problems when people naïvely
> > copy/paste the command into the shell prompt.
> 
> Users can copy-paste the first example as-is already, since the earlier line 
> ends in backslash.

Long lines without any backslashes are safer, so I'd prefer that.  But
I won't have another bikeshedding argument over that, so if you don't
feel like changing it, so be it.

> If we're talking about truly naive users, then these commands are too long 
> anyway.

I don't see any real problem with that, all supported platforms can
handle much longer commands.

> I'll hold off backporting until we get the important matter of backslashes 
> resolved. :-)

It's resolved already, if it's up to me.