Build Chromium OS from Ubuntu curl -fsSL URL_HERE | sh

build_chromium_os.sh

#!/bin/sh
set -xe

sudo apt-get install git-core gitk git-gui subversion curl lvm2 thin-provisioning-tools python-pkg-resources python-virtualenv python-oauth2client

# install depot tools
git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git
PATH=$PATH:/path/to/depot_tools

# Making sudo a little more permissive
cd /tmp
cat > ./sudo_editor <<EOF
#!/bin/sh
echo Defaults \!tty_tickets > \$1          # Entering your password in one shell affects all shells 
echo Defaults timestamp_timeout=180 >> \$1 # Time between re-requesting your password, in minutes
EOF
chmod +x ./sudo_editor 
sudo EDITOR=./sudo_editor visudo -f /etc/sudoers.d/relax_requirements

# Get source
mkdir ~/chromium_os_source
SOURCE_REPO=~/chromium_os_source
cd ${SOURCE_REPO}
repo init -u https://chromium.googlesource.com/chromiumos/manifest.git
# Optional: Make any changes to .repo/local_manifests/local_manifest.xml before syncing
repo sync

# Build for amd64
export BOARD=amd64-generic
cros_sdk -- ./build_packages --board=${BOARD}

# Build an image
cros_sdk -- ./build_image --board=${BOARD}