When using KICAD to make a PCB, the X sever crashes.
While the segfault is in libfb, it was called by the intel video server,
so I suspect the error there.

Occurred again after starting to continue the work in KICAD.

Dear Maintainer,

I have the same symptoms as the original reporter.  When using the KiCad
PCB layout program pcbnew, the X server repeatedly crashes with a
substantially similar backtrace to the OP.  I am using KiCad compiled
from source, bzr version 5054.  I have reproduced the backtrace here,
as it does not appear in the automatically-attached log.  I am running
a custom kernel for disk-related reasons, but as I am seeing the same
fault as the OP I do not suspect that this is a confounding factor.  I
can likely revert to mainline if that is absolutely necessary.

199651.255] Backtrace:
[199651.255] 0: /usr/bin/X (xorg_backtrace+0x36) [0x7f9f0b382d16]
[199651.255] 1: /usr/bin/X (0x7f9f0b204000+0x182869) [0x7f9f0b386869]
[199651.255] 2: /lib/x86_64-linux-gnu/libpthread.so.0 (0x7f9f0a52c000+0xf030) [0x7f9f0a53b030]
[199651.255] 3: /usr/lib/xorg/modules/libfb.so (fbBresSolid+0x1ce) [0x7f9f067488fe]
[199651.255] 4: /usr/lib/xorg/modules/libfb.so (fbSegment+0x40f) [0x7f9f06749cbf]
[199651.255] 5: /usr/lib/xorg/modules/libfb.so (fbPolySegment32+0x41c) [0x7f9f0673e33c]
[199651.255] 6: /usr/lib/xorg/modules/drivers/intel_drv.so (0x7f9f07182000+0xc4c85) [0x7f9f07246c85]
[199651.255] 7: /usr/bin/X (0x7f9f0b204000+0x112e3e) [0x7f9f0b316e3e]
[199651.255] 8: /usr/bin/X (0x7f9f0b204000+0x4f43d) [0x7f9f0b25343d]
[199651.255] 9: /usr/bin/X (0x7f9f0b204000+0x52e61) [0x7f9f0b256e61]
[199651.255] 10: /usr/bin/X (0x7f9f0b204000+0x41ec5) [0x7f9f0b245ec5]
[199651.255] 11: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xfd) [0x7f9f09251eed]
[199651.255] 12: /usr/bin/X (0x7f9f0b204000+0x4219d) [0x7f9f0b24619d]
[199651.255]
[199651.255] Segmentation fault at address 0x7f9f037b2ffc
[199651.255]
Fatal server error:
[199651.255] Caught signal 11 (Segmentation fault). Server aborting