crouton: X startup failure: "AddScreen/ScreenInit failed for driver 1"

$ sudo edit-chroot -all
name: xenial
encrypted: no
Entering /mnt/stateful_partition/crouton/chroots/xenial...
crouton: version 1-20170315143304~master:95589555
release: xenial
architecture: armhf
xmethod: xorg
targets: lxde,cli-extra
host: version 9000.91.0 (Official Build) stable-channel daisy 
kernel: Linux localhost 3.8.11 #1 SMP Wed Feb 22 23:16:02 PST 2017 armv7l armv7l armv7l GNU/Linux
freon: yes
Unmounting /mnt/stateful_partition/crouton/chroots/xenial...

Please describe your issue:

Crouton appears to work OK on Samsung XE303C12 chromebook. Everything installs and additional software can be installed and run via sudo apt install .... Crouton and shell can be exited safely and reopened without any issues. However it would seem that upon rebooting the chromebook, typing sudo startlxde fails to start X anymore. Sleep may also cause this issue - at first I thought this was random, but it seems reproducible on reboot. I would test this more but it takes a VERY long time to reinstall crouton.

I have reproduced this issue with lxde, xfce and unity.

Updating crouton with sudo sh ~/Downloads/crouton -n xenial -u does not fix the issue.

This is an example of the output:

$ sudo startlxde
Entering /mnt/stateful_partition/crouton/chroots/xenial...

_XSERVTransmkdir: Owner of /tmp/.X11-unix should be set to root

X.Org X Server 1.18.4
Release Date: 2016-07-19
X Protocol Version 11, Revision 0
Build Operating System: Linux 4.4.0-59-generic armv7l Ubuntu
Current Operating System: Linux localhost 3.8.11 #1 SMP Wed Feb 22 23:16:02 PST 2017 armv7l
Kernel command line: cros_secure console= console= loglevel=7 init=/sbin/init cros_secure oops=panic panic=-1 root=/dev/dm-0 rootwait ro dm_verity.error_behavior=3 dm_verity.max_bios=-1 dm_verity.dev_wait=1 dm="1 vroot none ro 1,0 2539520 verity payload=PARTUUID=d6b9cbba-f8c7-f54f-a3f1-b503bc9fdeb8/PARTNROFF=1 hashtree=PARTUUID=d6b9cbba-f8c7-f54f-a3f1-b503bc9fdeb8/PARTNROFF=1 hashstart=2539520 alg=sha1 root_hexdigest=0f8e46d1190f0b380a736dcc0160f1b5d0787ee9 salt=11b3c6f73efe039531fac6ea08ccfbea76bc7f4476fc063a443c9bdc614ba489" noinitrd vt.global_cursor_default=0 kern_guid=d6b9cbba-f8c7-f54f-a3f1-b503bc9fdeb8  
Build Date: 26 January 2017  12:27:19AM
xorg-server 2:1.18.4-1ubuntu6.1~16.04.1 (For technical support please see http://www.ubuntu.com/support) 
Current version of pixman: 0.33.6
        Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
        (++) from command line, (!!) notice, (II) informational,
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(++) Log file: "/tmp/Xorg.crouton.1.log", Time: Thu Mar 16 13:35:41 2017
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
gbm: failed to open any driver (search paths /usr/lib/arm-linux-gnueabihf/dri:${ORIGIN}/dri:/usr/lib/dri)
gbm: Last dlopen error: /usr/lib/dri/exynos_dri.so: cannot open shared object file: No such file or directory
failed to load driver: exynos
EGL_MESA_drm_image required.
(EE) 
Fatal server error:
(EE) AddScreen/ScreenInit failed for driver 1
(EE) 
(EE) 
Please consult the The X.Org Foundation support 
         at http://wiki.x.org
 for help. 
(EE) Please also check the log file at "/tmp/Xorg.crouton.1.log" for additional information.
(EE) 
(EE) Server terminated with error (1). Closing log file.

/usr/bin/xinit: giving up
/usr/bin/xinit: unable to connect to X server: Connection refused
/usr/bin/xinit: server error
Unmounting /mnt/stateful_partition/crouton/chroots/xenial...

The CLI seems to work fine though if I start the “xenial” chroot up using sudo startcli.

If known, describe the steps to reproduce the issue:

1. install crouton (sudo sh /downloads/crouton -t lxde,cli-extra)
2. run crouton OK (sudo startlxde)
3. logout of lxde, exit crouton, exit shell, close tab
4. Reboot device
5. Go to terminal (Ctrl+Alt+t)
6. Enter shell (type shell)
7. Attempt to start X (type sudo sudo startlxde)