I think there should be a possibility to activate the debug mode only for a special defined group of users.
So you would be able to switch on the debug mode on productive systems without disturbing the work of the rest of users.
I implemented it temporary as admin tool and integrated it into the settings page "admin/settings/development.php" and into the "lib/setup.php" to activate it.
I think it is an important improvement of the debug mode.
If you want to test it you can go to this page:
There are some users to test it.
user: testadmin, pw: 123.Test.xyz
user: usera1, pw: 123.User
user: usera2, pw: 123.User
user: usera3, pw: 123.User
With "testadmin" you can go to "Site administration/Development/Debugging" and try the new settings.
To see the debug messages I have put some wrong lines into the config.php ;).
The tracker for this extension is here http://tracker.moodle.org/browse/MDL-36687
If you find it useful it would be great to vote for it.
General developer forum
This would be SUPER useful. I hate turning on debug mode on my live sites, it only takes seconds before emails start pouring in to fix 'all the things'.
How do I vote?