Import make_chroot from chromiumos-overlay.

Imported as of 09d3117c483c60f55f552694b84b0964dfc17477.

Only modification is so that it can find common.sh.

BUG=chromium-os:25697
TEST=None

Change-Id: Idb43f1ecff3dff10a61396629a344c8bd10f505e
Reviewed-on: https://gerrit.chromium.org/gerrit/15317
Tested-by: Brian Harring <ferringb@chromium.org>
Reviewed-by: David James <davidjames@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Ready: Brian Harring <ferringb@chromium.org>
diff --git a/sdk_lib/make_chroot.sh b/sdk_lib/make_chroot.sh
new file mode 100755
index 0000000..8d60c55
--- /dev/null
+++ b/sdk_lib/make_chroot.sh
@@ -0,0 +1,481 @@
+#!/bin/bash
+
+# Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# This script sets up a Gentoo chroot environment. The script is passed the
+# path to an empty folder, which will be populated with a Gentoo stage3 and
+# setup for development. Once created, the password is set to PASSWORD (below).
+# One can enter the chrooted environment for work by running enter_chroot.sh.
+
+SCRIPT_ROOT=$(readlink -f $(dirname "$0")/..)
+. "${SCRIPT_ROOT}/common.sh" || exit 1
+
+# Check if the host machine architecture is supported.
+ARCHITECTURE="$(uname -m)"
+if [[ "$ARCHITECTURE" != "x86_64" ]]; then
+  echo "$SCRIPT_NAME: $ARCHITECTURE is not supported as a host machine architecture."
+  exit 1
+fi
+
+# Script must be run outside the chroot
+assert_outside_chroot
+
+# Define command line flags
+# See http://code.google.com/p/shflags/wiki/Documentation10x
+
+DEFINE_string chroot "$DEFAULT_CHROOT_DIR" \
+  "Destination dir for the chroot environment."
+DEFINE_boolean usepkg $FLAGS_TRUE "Use binary packages to bootstrap."
+DEFINE_boolean delete $FLAGS_FALSE "Delete an existing chroot."
+DEFINE_boolean replace $FLAGS_FALSE "Overwrite existing chroot, if any."
+DEFINE_integer jobs -1 "How many packages to build in parallel at maximum."
+DEFINE_boolean fast ${DEFAULT_FAST} "Call many emerges in parallel"
+DEFINE_string stage3_date "2010.03.09" \
+  "Use the stage3 with the given date."
+DEFINE_string stage3_path "" \
+  "Use the stage3 located on this path."
+DEFINE_boolean cros_sdk $FLAGS_FALSE "Internal: we're called from cros_sdk"
+
+# Parse command line flags
+FLAGS_HELP="usage: $SCRIPT_NAME [flags]"
+FLAGS "$@" || exit 1
+eval set -- "${FLAGS_ARGV}"
+check_flags_only_and_allow_null_arg "$@" && set --
+
+if [ "${FLAGS_cros_sdk}" == "${FLAGS_TRUE}" ]; then
+  # HACK: If we're being called by cros_sdk, change the messages.
+  SCRIPT_NAME=cros_sdk
+fi
+
+assert_not_root_user
+# Set the right umask for chroot creation.
+umask 022
+
+# Only now can we die on error.  shflags functions leak non-zero error codes,
+# so will die prematurely if 'set -e' is specified before now.
+# TODO: replace shflags with something less error-prone, or contribute a fix.
+set -e
+
+FULLNAME="ChromeOS Developer"
+DEFGROUPS="eng,adm,cdrom,floppy,audio,video,portage"
+PASSWORD=chronos
+CRYPTED_PASSWD=$(perl -e 'print crypt($ARGV[0], "foo")', $PASSWORD)
+
+USEPKG=""
+if [[ $FLAGS_usepkg -eq $FLAGS_TRUE ]]; then
+  # Use binary packages. Include all build-time dependencies,
+  # so as to avoid unnecessary differences between source
+  # and binary builds.
+  USEPKG="--getbinpkg --usepkg --with-bdeps y"
+fi
+
+# Support faster build if necessary.
+EMERGE_CMD="emerge"
+if [ "$FLAGS_fast" -eq "${FLAGS_TRUE}" ]; then
+  CHROOT_CHROMITE_DIR="/home/${USER}/trunk/chromite"
+  EMERGE_CMD="${CHROOT_CHROMITE_DIR}/bin/parallel_emerge"
+fi
+
+function in_chroot {
+  sudo "${CHROOT_PASSTHRU[@]}" chroot "$FLAGS_chroot" "$@"
+}
+
+function bash_chroot {
+  # Use $* not $@ since 'bash -c' needs a single arg
+  # Use -l to force source of /etc/profile (login shell)
+  sudo "${CHROOT_PASSTHRU[@]}" chroot "$FLAGS_chroot" bash -l -c "$*"
+}
+
+function sudo_chroot {
+  # The same as bash_chroot, except ran as the normal user.
+  sudo chroot "$FLAGS_chroot" sudo -i -u ${USER} "${CHROOT_PASSTHRU[@]}" -- "$@"
+}
+
+function cleanup {
+  # Clean up mounts
+  safe_umount_tree "${FLAGS_chroot}"
+}
+
+function delete_existing {
+  # Delete old chroot dir
+  if [[ -e "$FLAGS_chroot" ]]; then
+    echo "$SCRIPT_NAME: Cleaning up old mount points..."
+    cleanup
+    echo "$SCRIPT_NAME: Deleting $FLAGS_chroot..."
+    sudo rm -rf "$FLAGS_chroot"
+    echo "$SCRIPT_NAME: Done."
+  fi
+}
+
+function init_users () {
+   echo "$SCRIPT_NAME: Set timezone..."
+   # date +%Z has trouble with daylight time, so use host's info
+   in_chroot rm -f /etc/localtime
+   if [ -f /etc/localtime ] ; then
+     sudo cp /etc/localtime "${FLAGS_chroot}/etc"
+   else
+     in_chroot ln -sf /usr/share/zoneinfo/PST8PDT /etc/localtime
+   fi
+   echo "$SCRIPT_NAME: Adding user/group..."
+   # Add ourselves as a user inside the chroot.
+   in_chroot groupadd -g 5000 eng
+   # We need the UID to match the host user's. This can conflict with
+   # a particular chroot UID. At the same time, the added user has to
+   # be a primary user for the given UID for sudo to work, which is
+   # determined by the order in /etc/passwd. Let's put ourselves on top
+   # of the file.
+   in_chroot useradd -o -G ${DEFGROUPS} -g eng -u `id -u` -s \
+     /bin/bash -m -c "${FULLNAME}" -p ${CRYPTED_PASSWD} ${USER}
+   # Because passwd generally isn't sorted and the entry ended up at the
+   # bottom, it is safe to just take it and move it to top instead.
+   in_chroot sed -e '1{h;d};$!{H;d};$G' -i /etc/passwd
+}
+
+function init_setup () {
+   echo "$SCRIPT_NAME: Running init_setup()..."
+   sudo mkdir -p "${FLAGS_chroot}/usr"
+   sudo ln -sf "${CHROOT_TRUNK}/src/third_party/portage" \
+     "${FLAGS_chroot}/usr/portage"
+   sudo mkdir -p "${FLAGS_chroot}/usr/local/portage"
+   sudo chmod 755 "${FLAGS_chroot}/usr/local/portage"
+   sudo ln -sf "${CHROOT_TRUNK}/src/third_party/chromiumos-overlay" \
+     "${FLAGS_chroot}"/"${CHROOT_OVERLAY}"
+   sudo ln -sf "${CHROOT_TRUNK}/src/third_party/portage-stable" \
+     "${FLAGS_chroot}"/"${PORTAGE_STABLE_OVERLAY}"
+   sudo mkdir -p "${FLAGS_chroot}"/"${CROSSDEV_OVERLAY}"
+   sudo chmod 755 "${FLAGS_chroot}"/"${CROSSDEV_OVERLAY}"
+
+   # Some operations need an mtab
+   in_chroot ln -s /proc/mounts /etc/mtab
+
+   # Set up sudoers.  Inside the chroot, the user can sudo without a password.
+   # (Safe enough, since the only way into the chroot is to 'sudo chroot', so
+   # the user's already typed in one sudo password...)
+   # Make sure the sudoers.d subdir exists as older stage3 base images lack it.
+   sudo mkdir -p "${FLAGS_chroot}/etc/sudoers.d"
+   sudo_clobber "${FLAGS_chroot}/etc/sudoers.d/90_cros" <<EOF
+Defaults env_keep += CROS_WORKON_SRCROOT
+Defaults env_keep += CHROMEOS_OFFICIAL
+Defaults env_keep += PORTAGE_USERNAME
+Defaults env_keep += http_proxy
+Defaults env_keep += ftp_proxy
+Defaults env_keep += all_proxy
+%adm ALL=(ALL) ALL
+root ALL=(ALL) ALL
+$USER ALL=NOPASSWD: ALL
+EOF
+   bash_chroot "find /etc/sudoers* -type f -exec chmod 0440 {} +"
+   bash_chroot "chown -R root:root /etc/sudoers*" # Fix bad group for some.
+
+   echo "$SCRIPT_NAME: Setting up hosts/resolv..."
+   # Copy config from outside chroot into chroot
+   sudo cp /etc/hosts "$FLAGS_chroot/etc/hosts"
+   sudo chmod 0644 "$FLAGS_chroot/etc/hosts"
+   sudo cp /etc/resolv.conf "$FLAGS_chroot/etc/resolv.conf"
+   sudo chmod 0644 "$FLAGS_chroot/etc/resolv.conf"
+
+   # Setup host make.conf. This includes any overlay that we may be using
+   # and a pointer to pre-built packages.
+   # TODO: This should really be part of a profile in the portage
+   echo "$SCRIPT_NAME: Setting up /etc/make.*..."
+   sudo mv "${FLAGS_chroot}"/etc/make.conf{,.orig}
+   sudo ln -sf "${CHROOT_CONFIG}/make.conf.amd64-host" \
+     "${FLAGS_chroot}/etc/make.conf"
+   sudo mv "${FLAGS_chroot}"/etc/make.profile{,.orig}
+   sudo ln -sf "${CHROOT_OVERLAY}/profiles/default/linux/amd64/10.0" \
+     "${FLAGS_chroot}/etc/make.profile"
+
+   # Create make.conf.user
+   sudo touch "${FLAGS_chroot}"/etc/make.conf.user
+   sudo chmod 0644 "${FLAGS_chroot}"/etc/make.conf.user
+
+   # Create directories referred to by our conf files.
+   sudo mkdir -p -m 775 "${FLAGS_chroot}/var/lib/portage/distfiles"
+   sudo mkdir -p -m 775 "${FLAGS_chroot}/var/lib/portage/distfiles-target"
+   sudo mkdir -p -m 775 "${FLAGS_chroot}/var/lib/portage/pkgs"
+
+   if [[ $FLAGS_jobs -ne -1 ]]; then
+     EMERGE_JOBS="--jobs=$FLAGS_jobs"
+   fi
+
+   # Add chromite/bin and depot_tools into the path globally; note that the
+   # chromite wrapper itself might also be found in depot_tools.
+   # We rely on 'env-update' getting called below.
+   target="${FLAGS_chroot}/etc/env.d/99chromiumos"
+   sudo_clobber "${target}" <<EOF
+PATH=/home/$USER/trunk/chromite/bin:/home/$USER/depot_tools
+CROS_WORKON_SRCROOT="${CHROOT_TRUNK}"
+PORTAGE_USERNAME=$USER
+EOF
+
+   # TODO(zbehan): Configure stuff that is usually configured in postinst's,
+   # but wasn't. Fix the postinst's. crosbug.com/18036
+   echo "Running post-inst configuration hacks"
+   in_chroot env-update
+   if [ -f ${FLAGS_chroot}/usr/bin/build-docbook-catalog ]; then
+     # For too ancient chroots that didn't have build-docbook-catalog, this
+     # is not relevant, and will get installed during update.
+     in_chroot build-docbook-catalog
+   fi
+
+   # Configure basic stuff needed
+   in_chroot env-update
+   bash_chroot ls -l /etc/make.conf
+   bash_chroot ls -l /etc/make.profile
+   bash_chroot ls -l /usr/local/portage/chromiumos/profiles/default/linux/amd64/10.0
+
+   target="${FLAGS_chroot}/etc/profile.d"
+   sudo mkdir -p "${target}"
+   sudo_clobber "${target}/chromiumos-niceties.sh" << EOF
+# Niceties for interactive logins. (cr) denotes this is a chroot, the
+# __git_branch_ps1 prints current git branch in ./ . The $r behavior is to
+# make sure we don't reset the previous $? value which later formats in
+# $PS1 might rely on.
+PS1='\$(r=\$?; __git_branch_ps1 "(%s) "; exit \$r)'"\${PS1}"
+PS1="(cr) \${PS1}"
+EOF
+
+   # Select a small set of locales for the user if they haven't done so
+   # already.  This makes glibc upgrades cheap by only generating a small
+   # set of locales.  The ones listed here are basically for the buildbots
+   # which always assume these are available.  This works in conjunction
+   # with `cros_sdk --enter`.
+   # http://crosbug.com/20378
+   local localegen="$FLAGS_chroot/etc/locale.gen"
+   if ! grep -q -v -e '^#' -e '^$' "${localegen}" ; then
+     sudo_append "${localegen}" <<EOF
+en_US ISO-8859-1
+en_US.UTF-8 UTF-8
+EOF
+   fi
+
+   # Add chromite as a local site-package.
+   mkdir -p "${FLAGS_chroot}/home/$USER/.local/lib/python2.6/site-packages"
+   ln -s ../../../../trunk/chromite \
+     "${FLAGS_chroot}/home/$USER/.local/lib/python2.6/site-packages/"
+
+   chmod a+x "$FLAGS_chroot/home/$USER/.bashrc"
+   # Automatically change to scripts directory
+   echo 'cd ${CHROOT_CWD:-~/trunk/src/scripts}' \
+       >> "$FLAGS_chroot/home/$USER/.bash_profile"
+
+   # Enable bash completion for build scripts
+   echo ". ~/trunk/src/scripts/bash_completion" \
+       >> "$FLAGS_chroot/home/$USER/.bashrc"
+
+   # Warn if attempting to use source control commands inside the chroot
+   for NOUSE in svn gcl gclient
+   do
+     echo "alias $NOUSE='echo In the chroot, it is a bad idea to run $NOUSE'" \
+       >> "$FLAGS_chroot/home/$USER/.bash_profile"
+   done
+
+   if [[ "$USER" = "chrome-bot" ]]; then
+     # Copy ssh keys, so chroot'd chrome-bot can scp files from chrome-web.
+     cp -r ~/.ssh "$FLAGS_chroot/home/$USER/"
+   fi
+
+   if [[ -f $HOME/.gitconfig ]]; then
+     # Copy .gitconfig into chroot so repo and git can be used from inside
+     # This is required for repo to work since it validates the email address
+     echo "Copying ~/.gitconfig into chroot"
+     cp $HOME/.gitconfig "$FLAGS_chroot/home/$USER/"
+   fi
+}
+
+# Handle deleting an existing environment
+if [[ $FLAGS_delete  -eq $FLAGS_TRUE || \
+      $FLAGS_replace -eq $FLAGS_TRUE ]]; then
+  delete_existing
+  [[ $FLAGS_delete -eq $FLAGS_TRUE ]] && exit 0
+fi
+
+CHROOT_TRUNK="${CHROOT_TRUNK_DIR}"
+PORTAGE="${SRC_ROOT}/third_party/portage"
+OVERLAY="${SRC_ROOT}/third_party/chromiumos-overlay"
+CONFIG_DIR="${OVERLAY}/chromeos/config"
+CHROOT_CONFIG="${CHROOT_TRUNK}/src/third_party/chromiumos-overlay/chromeos/config"
+PORTAGE_STABLE_OVERLAY="/usr/local/portage/stable"
+CROSSDEV_OVERLAY="/usr/local/portage/crossdev"
+CHROOT_OVERLAY="/usr/local/portage/chromiumos"
+CHROOT_STATE="${FLAGS_chroot}/etc/debian_chroot"
+CHROOT_PASSTHRU=(CROS_WORKON_SRCROOT="$CHROOT_TRUNK" PORTAGE_USERNAME="$USER"
+                 IGNORE_PREFLIGHT_BINHOST="$IGNORE_PREFLIGHT_BINHOST")
+
+# Pass proxy variables into the environment.
+for type in http ftp all; do
+   value=$(env | grep ${type}_proxy || true)
+   if [ -n "${value}" ]; then
+      CHROOT_PASSTHRU+=("$value")
+   fi
+done
+
+# Create the base Gentoo stage3 based on last version put in chroot
+STAGE3="${OVERLAY}/chromeos/stage3/stage3-amd64-${FLAGS_stage3_date}.tar.bz2"
+if [ -f $CHROOT_STATE ] && \
+  ! sudo egrep -q "^STAGE3=$STAGE3" $CHROOT_STATE >/dev/null 2>&1
+then
+  echo "$SCRIPT_NAME: STAGE3 version has changed."
+  delete_existing
+fi
+
+if [ -n "${FLAGS_stage3_path}" ]; then
+  if [ -f "${FLAGS_stage3_path}" ]; then
+    STAGE3="${FLAGS_stage3_path}"
+  else
+    error "Invalid stage3!"
+    exit 1;
+  fi
+fi
+
+# Create the destination directory
+mkdir -p "$FLAGS_chroot"
+
+echo
+if [ -f $CHROOT_STATE ]
+then
+  echo "$SCRIPT_NAME: STAGE3 already set up.  Skipping..."
+else
+  echo "$SCRIPT_NAME: Unpacking STAGE3..."
+  sudo tar -xp -I $(type -p pbzip2 || echo bzip2) \
+      -C "${FLAGS_chroot}" -f "${STAGE3}"
+  sudo rm -f $FLAGS_chroot/etc/make.globals
+  sudo rm -f $FLAGS_chroot/etc/make.conf.user
+fi
+
+# Set up users, if needed, before mkdir/mounts below
+[ -f $CHROOT_STATE ] || init_users
+
+echo
+echo "$SCRIPT_NAME: Setting up mounts..."
+# Set up necessary mounts and make sure we clean them up on exit
+trap cleanup EXIT
+sudo mkdir -p "${FLAGS_chroot}/${CHROOT_TRUNK}"
+sudo mount --bind /dev "${FLAGS_chroot}/dev"
+sudo mount --bind "${GCLIENT_ROOT}" "${FLAGS_chroot}/${CHROOT_TRUNK}"
+sudo mount none -t proc "$FLAGS_chroot/proc"
+sudo mount none -t devpts "$FLAGS_chroot/dev/pts"
+sudo mkdir -p "${FLAGS_chroot}/run"
+if [ -d /run ]; then
+  sudo mount --bind /run "$FLAGS_chroot/run"
+  if [ -d /run/shm ]; then
+    sudo mount --bind /run/shm "$FLAGS_chroot/run/shm"
+  fi
+fi
+PREBUILT_SETUP="$FLAGS_chroot/etc/make.conf.prebuilt_setup"
+if [[ -z "$IGNORE_PREFLIGHT_BINHOST" ]]; then
+  echo 'PORTAGE_BINHOST="$FULL_BINHOST"' | sudo_clobber "$PREBUILT_SETUP"
+else
+  sudo_clobber "$PREBUILT_SETUP" < /dev/null
+fi
+sudo chmod 0644 "$PREBUILT_SETUP"
+
+# For bootstrapping from old wget, disable certificate checking. Once we've
+# upgraded to new curl (below), certificate checking is re-enabled. See
+# http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=409938
+bash_chroot 'cat > /etc/make.conf.fetchcommand_setup' <<'EOF'
+FETCHCOMMAND="/usr/bin/wget -t 5 -T 60 --no-check-certificate --passive-ftp -O \"\${DISTDIR}/\${FILE}\" \"\${URI}\""
+RESUMECOMMAND="/usr/bin/wget -c -t 5 -T 60 --no-check-certificate --passive-ftp -O \"\${DISTDIR}/\${FILE}\" \"\${URI}\""
+EOF
+sudo chmod 0644 "${FLAGS_chroot}"/etc/make.conf.fetchcommand_setup
+bash_chroot 'cat > /etc/make.conf.host_setup' <<EOF
+# Created by make_chroot
+source make.conf.prebuilt_setup
+source make.conf.fetchcommand_setup
+MAKEOPTS="-j${NUM_JOBS}"
+EOF
+sudo chmod 0644 "${FLAGS_chroot}"/etc/make.conf.host_setup
+
+if ! [ -f "$CHROOT_STATE" ];then
+  INITIALIZE_CHROOT=1
+fi
+
+
+if [ -z "${INITIALIZE_CHROOT}" ];then
+  echo "$SCRIPT_NAME: chroot already initialized.  Skipping..."
+else
+  # run all the init stuff to setup the env
+  init_setup
+fi
+
+# Add file to indicate that it is a chroot
+# Add version of $STAGE3 for update checks
+sudo sh -c "echo STAGE3=$STAGE3 > $CHROOT_STATE"
+
+echo "$SCRIPT_NAME: Updating portage"
+in_chroot emerge -uNv portage
+
+echo "$SCRIPT_NAME: Updating toolchain"
+in_chroot emerge -uNv $USEPKG '>=sys-devel/gcc-4.4' sys-libs/glibc \
+    sys-devel/binutils sys-kernel/linux-headers
+
+# HACK: Select the latest toolchain. We're assuming that when this is
+# ran, the chroot has no experimental versions of new toolchains, just
+# one that is very old, and one that was just emerged.
+CHOST="$(in_chroot portageq envvar CHOST)"
+LATEST="$(in_chroot gcc-config -l | grep "${CHOST}" | tail -n1 | \
+          cut -f3 -d' ')"
+in_chroot gcc-config "${LATEST}"
+in_chroot emerge --unmerge "<sys-devel/gcc-${LATEST/${CHOST}-/}"
+
+# dhcpcd is included in 'world' by the stage3 that we pull in for some reason.
+# We have no need to install it in our host environment, so pull it out here.
+echo "$SCRIPT_NAME: Deselecting dhcpcd"
+in_chroot $EMERGE_CMD --deselect dhcpcd
+
+echo "$SCRIPT_NAME: Running emerge ccache curl sudo ..."
+in_chroot $EMERGE_CMD -uNv $USEPKG ccache net-misc/curl sudo $EMERGE_JOBS
+
+# Curl is now installed, so we can depend on it now.
+bash_chroot 'cat > /etc/make.conf.fetchcommand_setup' <<'EOF'
+FETCHCOMMAND='curl -f -y 30 --retry 9 -L --output \${DISTDIR}/\${FILE} \${URI}'
+RESUMECOMMAND='curl -f -y 30 -C - --retry 9 -L --output \${DISTDIR}/\${FILE} \${URI}'
+EOF
+sudo chmod 0644 "${FLAGS_chroot}"/etc/make.conf.fetchcommand_setup
+
+if [ -n "${INITIALIZE_CHROOT}" ]; then
+  # If we're creating a new chroot, we also want to set it to the latest
+  # version.
+  sudo_chroot \
+      "${CHROOT_TRUNK}/src/scripts/run_chroot_version_hooks" --force_latest
+fi
+
+# Update chroot
+UPDATE_ARGS=""
+if [[ $FLAGS_usepkg -eq $FLAGS_TRUE ]]; then
+  UPDATE_ARGS+=" --usepkg"
+else
+  UPDATE_ARGS+=" --nousepkg"
+fi
+if [[ ${FLAGS_fast} -eq ${FLAGS_TRUE} ]]; then
+  UPDATE_ARGS+=" --fast"
+else
+  UPDATE_ARGS+=" --nofast"
+fi
+sudo_chroot "${CHROOT_TRUNK}/src/scripts/update_chroot" ${UPDATE_ARGS}
+
+# Unmount trunk
+sudo umount "${FLAGS_chroot}/${CHROOT_TRUNK}"
+
+# Clean up the chroot mounts
+trap - EXIT
+cleanup
+
+if [[ "$FLAGS_chroot" = "$DEFAULT_CHROOT_DIR" ]]; then
+  CHROOT_EXAMPLE_OPT=""
+else
+  CHROOT_EXAMPLE_OPT="--chroot=$FLAGS_chroot"
+fi
+
+print_time_elapsed
+
+echo
+echo "$SCRIPT_NAME: All set up.  To enter the chroot, run:"
+echo "$SCRIPT_NAME: $ cros_sdk --enter $CHROOT_EXAMPLE_OPT"
+echo ""
+echo "CAUTION: Do *NOT* rm -rf the chroot directory; if there are stale bind"
+echo "mounts you may end up deleting your source tree too.  To unmount and"
+echo "delete the chroot cleanly, use:"
+echo "$ $SCRIPT_NAME --delete $CHROOT_EXAMPLE_OPT"