Core was generated by `/usr/lib/Xorg :0 -seat seat0 -auth /run/lightdm/root/:0 -nolisten tcp vt7 -novt'.
Program terminated with signal SIGABRT, Aborted.
#0  0x00007f4f4316dd22 in raise () from /usr/lib/libc.so.6
[Current thread is 1 (Thread 0x7f4f427dd940 (LWP 347))]
(gdb) bt
#0  0x00007f4f4316dd22 in raise () at /usr/lib/libc.so.6
#1  0x00007f4f43157862 in abort () at /usr/lib/libc.so.6
#2  0x0000559db2cfda70 in OsAbort () at ../xorg-server-1.20.12/os/utils.c:1351
#3  0x0000559db2cff585 in AbortServer () at ../xorg-server-1.20.12/os/log.c:872
#4  FatalError
    (f=f@entry=0x559db2d8bed8 "Caught signal %d (%s). Server aborting\n")
    at ../xorg-server-1.20.12/os/log.c:1010
#5  0x0000559db2d0521a in OsSigHandler
    (unused=<optimized out>, sip=0x7ffda7d71330, signo=6)
    at ../xorg-server-1.20.12/os/osinit.c:156
#6  OsSigHandler (signo=6, sip=0x7ffda7d71330, unused=<optimized out>)
    at ../xorg-server-1.20.12/os/osinit.c:110
#7  0x00007f4f4316dda0 in <signal handler called> () at /usr/lib/libc.so.6
#8  0x00007f4f4316dd22 in raise () at /usr/lib/libc.so.6
#9  0x00007f4f43157862 in abort () at /usr/lib/libc.so.6
#10 0x00007f4f43157747 in _nl_load_domain.cold () at /usr/lib/libc.so.6
#11 0x00007f4f43166616 in  () at /usr/lib/libc.so.6
#12 0x00007f4f4239e9a5 in dixGetPrivateAddr
    (key=<optimized out>, privates=<optimized out>)
    at ../xorg-server-1.20.12/include/privates.h:121
#13 0x00007f4f423a7c26 in dixGetPrivateAddr
    (key=<optimized out>, privates=<optimized out>)
    at ../xorg-server-1.20.12/glamor/glamor_egl.c:359
#14 dixLookupPrivate
    (key=0x7f4f423cd900 <glamor_pixmap_private_key>, privates=0x559db5676760)
    at ../xorg-server-1.20.12/include/privates.h:164
#15 glamor_get_pixmap_private (pixmap=0x559db5676740)
    at ../xorg-server-1.20.12/glamor/glamor_priv.h:393
#16 glamor_make_pixmap_exportable
    (pixmap=pixmap@entry=0x559db5676740, modifiers_ok=modifiers_ok@entry=1)
    at ../xorg-server-1.20.12/glamor/glamor_egl.c:270
#17 0x00007f4f423a7c4e in glamor_gbm_bo_from_pixmap
    (screen=0x559db4bfaa40, pixmap=0x559db5676740)
    at ../xorg-server-1.20.12/glamor/glamor_egl.c:379
#18 0x00007f4f42441a34 in ms_present_check_unflip
    (pixmap=0x559db5676740, reason=0x7ffda7d71c34, sync_flip=<optimized out>, crtc=<optimized out>, window=<optimized out>, window=<optimized out>)
    at ../xorg-server-1.20.12/hw/xfree86/drivers/modesetting/present.c:262
#19 0x0000559db2c87219 in present_check_flip
    (crtc=0x559db4e969d0, window=0x559db4e03560, pixmap=0x559db5676740, sync_flip=1, valid=0x0, x_off=<optimized out>, y_off=0, reason=0x7ffda7d71c34)
    at ../xorg-server-1.20.12/present/present_scmd.c:138
#20 0x0000559db2c8cc3b in present_vblank_create
    (window=window@entry=0x559db4e03560, pixmap=pixmap@entry=0x559db5676740, serial=serial@entry=0, valid=valid@entry=0x0, update=update@entry=0x559db4f8d910, x_off=x_off@entry=0, y_off=0, target_crtc=0x559db4e969d0, wait_fence=0x0, idle_fe--Type <RET> for more, q to quit, c to continue without paging--
nce=0x0, options=0, capabilities=0x7f4f4244d9d0 <ms_present_screen_info+48>, notifies=0x0, num_notifies=0, target_msc=1, crtc_msc=0)
    at ../xorg-server-1.20.12/present/present_vblank.c:120
#21 0x0000559db2c8d183 in present_scmd_pixmap
    (window=<optimized out>, pixmap=0x559db5676740, serial=0, valid=0x0, update=0x559db4f8d910, x_off=<optimized out>, y_off=0, target_crtc=0x559db4e969d0, wait_fence=0x0, idle_fence=0x0, options=0, window_msc=<optimized out>, divisor=1, remainder=0, notifies=0x0, num_notifies=0)
    at ../xorg-server-1.20.12/present/present_scmd.c:745
#22 0x0000559db2c8bf66 in present_pixmap
    (num_notifies=0, notifies=0x0, remainder=<optimized out>, divisor=<optimized out>, window_msc=<optimized out>, options=<optimized out>, idle_fence=<optimized out>, wait_fence=<optimized out>, target_crtc=0x0, y_off=<optimized out>, x_off=<optimized out>, update=<optimized out>, valid=<optimized out>, serial=<optimized out>, pixmap=0x559db5676740, window=0x559db4e03560)
    at ../xorg-server-1.20.12/present/present.c:208
#23 proc_present_pixmap (client=<optimized out>)
    at ../xorg-server-1.20.12/present/present_request.c:150
#24 0x0000559db2beb89c in Dispatch ()
    at ../xorg-server-1.20.12/dix/dispatch.c:478
#25 dix_main (envp=<optimized out>, argv=<optimized out>, argc=<optimized out>)
    at ../xorg-server-1.20.12/dix/main.c:276
#26 main (argc=10, argv=0x7ffda7d72038, envp=<optimized out>)
    at ../xorg-server-1.20.12/dix/stubmain.c:34