I believe I am seeing the same bug (similar symptoms, similar X backtrace). It is triggered simply by logging out on some other VT; multiple X servers are not required. To reproduce on a freshly-booted machine:
- log in (on VT1) - startx - switch to VT2 - log in - log out At this point, instead of leaving me on VT2 with a login prompt, it automatically switches back to VT1, which is stuck as Brian describes. Brian, can you reproduce this? If so, I suggest changing the bug title to something like: xserver-xorg-core: crash/freeze on logout on another vt There appears to be some non-determinism: - Sometimes the VT1 terminal still shows the mouse pointer (on the otherwise empty i3 desktop); sometimes not. (On attempting to switch to a different VT, the mouse pointer, if still present, always disappears.) - During my many trials, in a single case, logging out on VT2 worked as expected, except that screen brightness was very low. I'm using an up-to-date Stretch, with rootless X and no display manager, using the i915 GPU driver (like Brian apparently, but with a different Intel graphics controller, "00:02.0 VGA compatible controller [0300]: Intel Corporation Core Processor Integrated Graphics Controller [8086:0046] (rev 02)").
