Crash when starting an external process

Crash when starting an external process

[Robert Woodworth]

Help!

Ubuntu 7.04

My emacs is suddenly crashing every time I start an external process.  
I've tried "shell" "compile" "gdb" etc...
The entire emacs process crashes with an "exit normally" return.  ??

Just for kicks, I uninstalled the Ubuntu dpkg and re-installed it.  -no fix-
I also uninstalled the dpkg and compiled emacs 22.1 from source and *HAD 
THE SAME PROBLEM*



So....
I must have a link, env var or some other system thing wrong.

What debug items can I turn on so that I know what is happening when I 
try to start an external process??

Re: Crash when starting an external process

[Peter Dyballa]

Am 24.07.2007 um 22:27 schrieb Robert Woodworth:

> What debug items can I turn on so that I know what is happening  
> when I try to start an external process??

When you run 'emacs --help' it gives some pointers. Particularly --no- 
init-file (-q) and --no-site-file are useful to exclude any init file  
as the culprit; --no-window-system (-nw) can help exclude X11.  
Finally --debug-init can help to shed some light on the Lisp code  
causing the crash.

--
Greetings

   Pete

If my theory of relativity is proven successful, Germany will claim  
me as a German, and France will declare that I am a citizen of the  
world. Should my theory prove untrue, France will say that I am a  
German, and Germany will declare that I am a Jew.
                                                 -- Albert Einstein,  
1929

Re: Crash when starting an external process

[Nick Roberts]

Robert Woodworth writes:
 > Help!
 > 
 > Ubuntu 7.04
 > 
 > My emacs is suddenly crashing every time I start an external process.  
 > I've tried "shell" "compile" "gdb" etc...
 > The entire emacs process crashes with an "exit normally" return.  ??
 > 
 > Just for kicks, I uninstalled the Ubuntu dpkg and re-installed it.  -no fix-
 > I also uninstalled the dpkg and compiled emacs 22.1 from source and *HAD 
 > THE SAME PROBLEM*
 > 
 > 
 > 
 > So....
 > I must have a link, env var or some other system thing wrong.
 > 
 > What debug items can I turn on so that I know what is happening when I 
 > try to start an external process??

Follow the instructions in report-emacs-bug, i.e. start Emacs in GDB and
then start an external process to get it to crash:

   If Emacs crashed, and you have the Emacs process in the gdb debugger,
   please include the output from the following gdb commands:
       `bt full' and `xbacktrace'.

Please do this with the most up to date version of Emacs that you have.

-- 
Nick                                           http://www.inet.net.nz/~nickrob

Re: Crash when starting an external process

[Robert Woodworth]

Did that, however, emacs is exiting *normally*.   So there is nothing in
the BackTrace.

Something is telling emacs to quit when I issue a shell command.

I have yet to really look at the source code, but if anyone out there
knows what file has the routine for the shell commands, I could put a
breakpoint there and watch it.  Or if there is just a way to turn on all
debug printfs.




BTW:  I have eliminated anything in the .emacs and system file by
repeating the issue with --debug-init and --no-init-file --no-site-file 





On Wed, 2007-07-25 at 10:20 +1200, Nick Roberts wrote:
> Robert Woodworth writes:
>   > Help!
>  > 
>  > Ubuntu 7.04
> 
>  > My emacs is suddenly crashing every time I start an external process.  
>  > I've tried "shell" "compile" "gdb" etc...
>  > The entire emacs process crashes with an "exit normally" return.  ??
>  > 
>  > Just for kicks, I uninstalled the Ubuntu dpkg and re-installed it.  -no fix-
>  > I also uninstalled the dpkg and compiled emacs 22.1 from source and *HAD 
>  > THE SAME PROBLEM*

>  > 
>  > My emacs is suddenly crashing every time I start an external process.  
>  > I've tried "shell" "compile" "gdb" etc...
>  > The entire emacs process crashes with an "exit normally" return.  ??
>  > 
>  > Just for kicks, I uninstalled the Ubuntu dpkg and re-installed it.  -no fix-
>  > I also uninstalled the dpkg and compiled emacs 22.1 from source and *HAD 
>  > THE SAME PROBLEM*
>  > 
>  > 
>  > 
>  > So....
>  > I must have a link, env var or some other system thing wrong.
>  > 
>  > What debug items can I turn on so that I know what is happening when I 
>  > try to start an external process??
> 
> Follow the instructions in report-emacs-bug, i.e. start Emacs in GDB and
> then start an external process to get it to crash:
> 
>    If Emacs crashed, and you have the Emacs process in the gdb debugger,
>    please include the output from the following gdb commands:
>        `bt full' and `xbacktrace'.
> 
> Please do this with the most up to date version of Emacs that you have.
> 

Re: Crash when starting an external process

[Nick Roberts]

 > Did that, however, emacs is exiting *normally*.   So there is nothing in
 > the BackTrace.

My understanding is that a crash is an abnormal exit, so I presume that in
your case Emacs is not crashing.  Does it happen if you start Emacs 22.1
with "emacs -Q" or "emacs -q"?  If no, then you need to look at site local
files like your .emacs.  If yes, then after starting Emacs under GDB, set a
breakpoint at Fkill_emacs:

(gdb) b Fkill_emacs
(gdb) run

After you start an external process doe this catch Emacs before it exits?
If so, please post this backtrace (`bt full' and `xbacktrace').

-- 
Nick                                           http://www.inet.net.nz/~nickrob

Re: Crash when starting an external process

[Tim X]

Robert Woodworth <woodworth@speakeasy.net> writes:

> Did that, however, emacs is exiting *normally*.   So there is nothing in
> the BackTrace.
>
> Something is telling emacs to quit when I issue a shell command.
>
> I have yet to really look at the source code, but if anyone out there
> knows what file has the routine for the shell commands, I could put a
> breakpoint there and watch it.  Or if there is just a way to turn on all
> debug printfs.
>
>
>
>
> BTW:  I have eliminated anything in the .emacs and system file by
> repeating the issue with --debug-init and --no-init-file --no-site-file 
>

Are you running emacs from X, from within a X terminal or from the console?
Have you been able to reproduce the problem in all three above situations? 

The reason I asked is that it *could* be something in the shell you are running
emacs within - possibly setting something that is affecting signal handling
or some environment variable thats being inherited etc. 

Its a very long shot, but I do remember once having problems with a program
that was just exiting and giving no indication of any problem. It turned out
that a script in a parent shell was setting something via a command line switch
(I wish I could remember exactly what it was) that caused the program to exit
abruptly. While its unlikely this is the problem in your case, it might be
worth running emacs under the different scenarios and maybe even running it
under different shells to see if you get the same behavior. 

Tim

-- 
tcross (at) rapttech dot com dot au