• Install dependencies:

sudo apt-get install dchroot

• Create necessary directories:

sudo mkdir -p /srv/chroots/

• Download the pre-made chroot image and uncompress it:

cd /srv/chroots/
wget arcoslab.eie.ucr.ac.cr/sid-amd64-2013.02.25-rosbase.tar.bz2
tar -xjf sid-amd64-2013.02.25-rosbase.tar.bz2

• Create a script for mounting, entering, exiting and unmounting the necessary system directories (this is instead of using the fstab file which can be dangerous when, for example, you decide to delete the chroot with the system directories still mounted. If you do rm -rf /srv/chroots/sid-amd64-2013.02.25-rosbase, you may not only delete the chroot directory but the system directories as well!!): This is the script: (copy it to /usr/local/bin/sid-amd64-2013.02.25-rosbase.sh)

#!/bin/bash
CHROOT_DIR=/srv/chroots/
CHROOT_NAME=`basename $0 .sh` 

if [ ! -e /var/run/$CHROOT_NAME ]
then
    sudo touch /var/run/$CHROOT_NAME
    sudo bash -c "echo 1 > /var/run/$CHROOT_NAME"
else
    sudo bash -c "echo `expr 1 + \`cat /var/run/$CHROOT_NAME\`` > /var/run/$CHROOT_NAME"
fi

if [ `cat /var/run/$CHROOT_NAME` -eq 1 ]
then
    echo "First chroot invocation. Mounting host system directories"
    sudo mkdir -p $CHROOT_DIR/$CHROOT_NAME/hostfs
    #mount -o bind /home/ $CHROOT_DIR/$CHROOT_NAME/home
    sudo mount proc -t proc $CHROOT_DIR/$CHROOT_NAME/proc
    sudo mount -o bind /dev $CHROOT_DIR/$CHROOT_NAME/dev
    sudo mount sys -t sysfs $CHROOT_DIR/$CHROOT_NAME/sys
    sudo mount none -t devpts $CHROOT_DIR/$CHROOT_NAME/dev/pts
    sudo mount -o bind / $CHROOT_DIR/$CHROOT_NAME/hostfs
fi

echo "Starting chroot."
#dchroot -c $CHROOT_NAME
sudo chroot $CHROOT_DIR/$CHROOT_NAME su - $USER
echo "Chroot closed."

if [ `cat /var/run/$CHROOT_NAME` -eq 1 ]
then
    echo "Closing last invocation. Unmounting host system directories"
    for i in dev/pts hostfs proc dev sys
    do
  sudo umount $CHROOT_DIR/$CHROOT_NAME/$i
        sleep 0.5
    done
fi

sudo bash -c "echo `expr \`cat /var/run/$CHROOT_NAME\` - 1` > /var/run/$CHROOT_NAME"

if [ `cat /var/run/$CHROOT_NAME` -eq 0 ]
then
    sudo rm /var/run/$CHROOT_NAME
fi

• Please remember to name the above script with a name exactly as the directory where the chroot is plus “.sh” at the end. The script uses this name to find the chroot and to do other things.
• Also, don't forget to give execute permissions to this script.

• Now configure the /etc/schroot/schroot.conf file with: (please use between the [] the exact same name of the subdirectory containing the chroot, otherwise the script will not work)

[sid-amd64-2013.02.25-rosbase]
description=Debian sid (unstable)
directory=/srv/chroots/sid-amd64-2013.02.25-rosbase
users=memeruiz    # CHANGE!!!!
#groups=sbuild                                                                  
root-groups=root
aliases=unstable,default   
preserve-environment=true

Now you are done. With:

sid-amd64-2013.02.25-rosbase.sh

You will get your chroot running. (this will not work because you don't have your same user in chroot yet, look down)

• Start the chroot as root user:

sudo sid-amd64-2013.02.25-rosbase.sh

• Add a normal user

adduser username

If you have questions regarding chroot please check Debian Unstable inside a Chroot for more information.