Merge lp:~ted/apport/enable-debug into lp:~apport-hackers/apport/trunk

[Ted Gould]

Add Upstart user session job to include debug information.

This comes from a discussion that seb and I were having where we thought it would be cool if when apport is collecting reports, we could also get all the debug messages in the upstart logs. Thinking about it more, I think that just having an apport job is probably the easiest way to do this.

[Martin Pitt (pitti)]

I'm not quite sure how these session upstart jobs work, what will that do exactly? We certainly shouldn't set G_MESSAGES_DEBUG=all for all session processes. I'm not even sure it's wise to set this for all session upstart activated services; debug messages can be *very* chatty, we would suddenly end up writing ten times the amount of data to log files which fills up the disk and causes a lot more I/O and wakeups.

I think we should make it as easy as possible to enable this, so that we can ask bug reporters to enable it for a while if necessary?

review: Needs Information

[Ted Gould (ted)]

On Wed, 2013-08-28 at 04:39 +0000, Martin Pitt wrote:

> I'm not quite sure how these session upstart jobs work, what will that do exactly? We certainly shouldn't set G_MESSAGES_DEBUG=all for all session processes. I'm not even sure it's wise to set this for all session upstart activated services; debug messages can be *very* chatty, we would suddenly end up writing ten times the amount of data to log files which fills up the disk and causes a lot more I/O and wakeups.
>
> I think we should make it as easy as possible to enable this, so that we can ask bug reporters to enable it for a while if necessary?

Yes, it would. I guess I don't feel that we have "bug reporters" we
have "bugs". I don't think that we can go back and forth on many of the
bugs, and I'd rather start getting the data when things *start*
happening not afterwards (which is basically a stacktrace). That way we
can know the story leading up to it.

If we're worried about the number of writes I imagine that Upstart can
optimize it's log writing to batch them some. But I'd rather start
getting to more fixable bugs on development releases.

[Martin Pitt (pitti)]

Still, I don't feel we should penalize millions of users with constant disk writes and filling up log files just becaus we want to look at a tiny tiny subset of these errors. We can do that in a more targetted way with the "collect extra information" hooks that can be requested by a developer for a particular crash report (that's somewhere in Evans mid-term plans). Also, for e. g. gnome-settings-daemon you'd need to specify an additional --debug before it actually works; but then it becomes *really* chatty and can easily accumulate several MB of logs.

As I said I'm fine with shipping the upstart job which doesn't start automatically, and provide a simple command to turn it on and off (using a per-user upstart override, for example).

This should be done in the ubuntu saucy branch only, not in trunk (but it's easy to merge it there instead of trunk).

[Dimitri John Ledkov (xnox)]

one can trivially do
echo export G_MESSAGES_DEBUG=all > ~/.config/upstart/a-job.override

To enable debug messages for a particular job. Or even it set that environmental variable for particular jobs etc. None of which requires editing a global conffile. I wouldn't want to ship such global job, especially when only a limited subset supports G_MESSAGES_DEBUG=all in the first place.

review: Disapprove

Unmerged revisions

2693. By Ted Gould on 2013-08-28

Too many equals

2692. By Ted Gould on 2013-08-28

Install the job in the right place

2691. By Ted Gould on 2013-08-28

Adding an apport job to set debug info if we're collecting apport bugs

=== added file 'data/apport-debug-enabled.conf'
--- data/apport-debug-enabled.conf	1970-01-01 00:00:00 +0000
+++ data/apport-debug-enabled.conf	2013-08-28 02:09:45 +0000
@@ -0,0 +1,12 @@
+description "Apport Enable Debug"
+
+start on starting dbus
+task
+
+script
+	ENABLED=`grep enabled /etc/default/apport | cut -d = -f 2`
+
+	if [ "x$ENABLED" = "x1" ]; then
+		initctl set-env --global G_MESSAGES_DEBUG=all
+	fi
+end script

=== modified file 'setup.py'
--- setup.py	2012-10-01 09:56:16 +0000
+++ setup.py	2013-08-28 02:09:45 +0000
@@ -124,6 +124,7 @@
                 ('share/apport/testsuite/', glob('test/*')),
                 ('share/doc/apport/', glob('doc/*.txt')),
                 ('lib/pm-utils/sleep.d/', glob('pm-utils/sleep.d/*')),
+                ('share/upstart/sessions/', glob('data/*.conf')),
                 ] + optional_data_files,
     cmdclass=cmdclass
 )