Easy chromium OS

Download from http://arnoldthebat.co.uk/wordpress/ http://arnoldthebat.co.uk/wordpress/chromium-os/
user@hostname:chromium-OS > 7z e Cx86OS_R42-6813.0-Special.7z 

7-Zip [64] 9.20  Copyright (c) 1999-2010 Igor Pavlov  2010-11-18
p7zip Version 9.20 (locale=en_GB.UTF-8,Utf16=on,HugeFiles=on,12 CPUs)

Processing archive: Cx86OS_R42-6813.0-Special.7z

Extracting  chromiumos_image.img

Everything is Ok

Size:       2589949952
Compressed: 337127396

Now, At the shell, run the following (where sdX is your USB stick and chromiumos_image.img is the path to the IMG file you extracted):
dd if=ChromeOS.img of=/dev/sdX bs=4M/
All builds based on x86 and ARM generic board. If you want to install your build to the SSD, open a shell and type
sudo /usr/sbin/chromeos-install
Note: This will replace EVERYTHING on your SSD. Use a recovery image if you want to get back to a stock Chrome OS build. Have fun!
git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git
export PATH="$PATH":thepathto/depot_tools
cd  cr_os

## line below did not work
repo init -u https://chromium.googlesource.com/chromiumos/manifest.git --depth=1 -b stabilize-6436.B

## This works
repo init -u https://chromium.googlesource.com/chromiumos/manifest.git  -g minilayout

repo sync
export BOARD=x86-generic

cros_sdk -- ./build_packages --board=${BOARD}
cros_sdk -- ./build_image --board=${BOARD}

[249996.300444] scsi 16:0:0:0: Direct-Access     Kingston DataTraveler G3  PMAP PQ: 0 ANSI: 0 CCS
[249996.301905] sd 16:0:0:0: Attached scsi generic sg1 type 0
[249997.142448] sd 16:0:0:0: [sdb] 7819264 512-byte logical blocks: (4.00 GB/3.72 GiB)

cros flash usb:///dev/sdc path/to/image

cros_sdk -- ./image_to_usb.sh --board=${BOARD} --to /dev/sdb
No image name specified, autodetecting...
Found default image chromiumos_image.bin
Copying image /mnt/host/source/src/build/images/x86-generic/R27-3820.0.2013_03_10_2019-a1/chromiumos_image.bin to device /dev/sdb...
WARNING : this will erase all data on /dev/sdb: Kingston DataTraveler G3, 0xd13b89c2
Are you sure (y/N)? y


7za e -t7z -so chromiumos-R27-3900.0.2013_03_24_2105-a1-x86-generic.bin.7z | pv -w 80 -s 2420m | dd of=/dev/sdb bs=4M oflag=sync status=noxfer