code review 7069060: run.bash: set GOTRACEBACK=2

run.bash: set GOTRACEBACK=2
This is useful to debug episodic crashes.

[dvyukov, 2013-01-09 07:21:25]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://dvyukov%40google.com@code.google.com/p/go/

[minux1, 2013-01-09 09:42:03]

consider also update run.rc?
changes to run.bash and run.bat LGTM.

[dvyukov, 2013-01-09 09:58:49]

Done

https://codereview.appspot.com/7069060/diff/8001/src/run.rc
File src/run.rc (right):

https://codereview.appspot.com/7069060/diff/8001/src/run.rc#newcode8
src/run.rc:8: export GOTRACEBACK=2
What should I use here: set or export?

[ality, 2013-01-09 10:13:59]

dvyukov@google.com once said:
> https://codereview.appspot.com/7069060/diff/8001/src/run.rc
> File src/run.rc (right):
> 
> https://codereview.appspot.com/7069060/diff/8001/src/run.rc#newcode8
> src/run.rc:8: export GOTRACEBACK=2
> What should I use here: set or export?

Just set the variable:

    GOTRACEBACK = 2

And add 'rfork e' above line 6 so run.rc
will use a seperate environment group.

Thanks,
  Anthony

https://codereview.appspot.com/7069060/

[minux1, 2013-01-09 10:16:13]

I just take a look at run.rc, and I think there are other problems.
(for example, `go env` doesn't support the -9 flag, and I believe
it should be `go tool dist env -9`), so your changes LGTM.

https://codereview.appspot.com/7069060/diff/8001/src/run.rc
File src/run.rc (right):

https://codereview.appspot.com/7069060/diff/8001/src/run.rc#newcode8
src/run.rc:8: export GOTRACEBACK=2
On 2013/01/09 09:58:49, dvyukov wrote:
> What should I use here: set or export?
just:
GOTRACEBACK=2

[dvyukov, 2013-01-09 10:17:18]

On 2013/01/09 10:13:59, ality wrote:
> mailto:dvyukov@google.com once said:
> > https://codereview.appspot.com/7069060/diff/8001/src/run.rc
> > File src/run.rc (right):
> > 
> > https://codereview.appspot.com/7069060/diff/8001/src/run.rc#newcode8
> > src/run.rc:8: export GOTRACEBACK=2
> > What should I use here: set or export?
> 
> Just set the variable:
> 
>     GOTRACEBACK = 2
> 
> And add 'rfork e' above line 6 so run.rc
> will use a seperate environment group.
> 
> Thanks,
>   Anthony
> 
> https://codereview.appspot.com/7069060/

Done
But I don't know what I am doing :)

[rsc, 2013-01-09 19:52:27]

Please revert this CL and try this instead (gmail threw away my tabs
but you should be able to read it):

diff -r 7314824cf6b8 src/pkg/runtime/panic.c
--- a/src/pkg/runtime/panic.c Sun Jan 06 22:44:16 2013 -0500
+++ b/src/pkg/runtime/panic.c Wed Jan 09 14:51:43 2013 -0500
@@ -454,6 +454,7 @@
 void
 runtime·throw(int8 *s)
 {
+ runtime·throwing = 1;
  runtime·startpanic();
  runtime·printf("fatal error: %s\n", s);
  runtime·dopanic(0);
diff -r 7314824cf6b8 src/pkg/runtime/symtab.c
--- a/src/pkg/runtime/symtab.c Sun Jan 06 22:44:16 2013 -0500
+++ b/src/pkg/runtime/symtab.c Wed Jan 09 14:51:43 2013 -0500
@@ -563,6 +563,8 @@
 {
  static int32 traceback = -1;

+ if(runtime·throwing)
+ return 1;
  if(traceback < 0)
  traceback = runtime·gotraceback();
  return traceback > 1 || contains(f->name, ".") &&
!hasprefix(f->name, "runtime.");

If it works, please send it out.

This will have the benefit of showing the frames even outside of all.bash.

Russ

[dvyukov, 2013-01-12 13:46:39]

*** Abandoned ***