100% reproducible segfault clicking "detect displays"

[Chris West]

When I click "Detect displays", nvidia-settings segfaults.

The nvidia driver doesn't seem particularly happy with having more than one monitor attached anyway (weird flashing during boot), but it does work if configured manually with xrandr. i3wm without gnome-session or any compositor running.

Full stacktrace from a custom build of the package (make X_CFLAGS=-g), for debug symbols:
(gdb) bt
#0 0x00007ffff6b9f13f in poll_for_next_event (c=0x0, queued=queued@entry=0) at ../../src/xcb_in.c:633
#1 0x00007ffff6b9f1b7 in xcb_poll_for_event (c=<optimised out>) at ../../src/xcb_in.c:647
#2 0x00007ffff78d5db8 in poll_for_event (dpy=dpy@entry=0x995720) at ../../src/xcb_io.c:257
#3 0x00007ffff78d5efe in poll_for_response (dpy=dpy@entry=0x995720) at ../../src/xcb_io.c:289
#4 0x00007ffff78d61dd in _XEventsQueued (dpy=dpy@entry=0x995720, mode=mode@entry=2) at ../../src/xcb_io.c:363
#5 0x00007ffff78c8207 in XPending (dpy=0x995720) at ../../src/Pending.c:55
#6 0x00000000004166ce in NvCtrlEventHandlePending ()
#7 0x00007ffff641c7da in () at /usr/lib/libnvidia-gtk3.so.346.59
#8 0x00007ffff41f83fd in g_main_context_prepare (context=context@entry=0x694810, priority=priority@entry=0x7fffffffe090)
    at /build/buildd/glib2.0-2.44.0/./glib/gmain.c:3410
#9 0x00007ffff41f8de8 in g_main_context_iterate (context=0x694810, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimised out>)
    at /build/buildd/glib2.0-2.44.0/./glib/gmain.c:3788
#10 0x00007ffff41f9242 in g_main_loop_run (loop=0x109df40) at /build/buildd/glib2.0-2.44.0/./glib/gmain.c:4002
#11 0x00007ffff5d03d15 in gtk_main () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#12 0x000000000040802b in main ()

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: nvidia-settings 346.59-0ubuntu1
ProcVersionSignature: Ubuntu 3.19.0-18.18-generic 3.19.6
Uname: Linux 3.19.0-18-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.17.2-0ubuntu1.1
Architecture: amd64
Date: Fri Jun 5 17:03:45 2015
InstallationDate: Installed on 2014-08-01 (308 days ago)
InstallationMedia: Ubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.2)
SourcePackage: nvidia-settings
UpgradeStatus: Upgraded to vivid on 2014-09-11 (267 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Ville Ranki (ville-ranki)]

Can reproduce this. I have lenovo E540 laptop with dual nvidia/intel graphics in nvidia mode. An external monitor is connected via HDMI, but I can't get it to be detected. Ubuntu is up to date 15.04 on x86.

[Luzius Thöny (lucius-antonius)]

Happens to me using Xubuntu 15.10 on a Lenovo Thinkpad laptop with the proprietary Nvidia drivers. The external projector is a Sony (not sure about the exact type). I can open nvidia-settings, but the projector is not recognized. When I click on "Detect Display", it crashes immediately with a segfault.