@Gilles, as @Celada found, the question had already been asked before. Yes "avoid loop altogether" goes maybe a bit too far. But adding "to process text" is not necessarily enough (though is right in 99.9% of the case, which is why the dup question focuses on that).
@FaheemMitha Thank you for your response, but I think I might need some interactive form of problem solving, as right now my problem is not very specific. I only have a couple of log snippets and a non-working screen.
@FaheemMitha I guess it is better to move to a Debian forum for that one.
You are trying to send the output to an external screen?
@HenriMenke Ok. I don't think the problem is with X. Your log (if you have posted the correct one) shows no errors. The problem is that nothing happens when you plug in your external monitor, right? It doesn't pick up the signal?
Have you tried restarting X with the monitor plugged in?
With wheezy, if you plugged in your monitor, did it pick up the signal immediately?
is there a tool which enables one to:
remember current RandR configuration (position, orientation, resolution etc) on per-monitor basis,
automatically apply last known good configuration as soon as the display is plugged in, with no need to muck around with applets or xrandr(1)?
@FaheemMitha The failure must occur one layer below all of this, because /sys/class/drm/card0-DP-1/status always contains disconnected and udevadm monitor does not report anything when plugging in and out the external display.