[ -n "$DEBIAN_FRONTEND" ] && echo "DEBIAN_FRONTEND=\"$DEBIAN_FRONTEND\"" >> $CHROOT_VARIABLES
[ -n "$DEBOOTSTRAP" ] && echo "DEBOOTSTRAP=\"$DEBOOTSTRAP\"" >> $CHROOT_VARIABLES
[ -n "$EXTRAPACKAGES" ] && echo "EXTRAPACKAGES=\"$EXTRAPACKAGES\"" >> $CHROOT_VARIABLES
[ -n "$DEBIAN_FRONTEND" ] && echo "DEBIAN_FRONTEND=\"$DEBIAN_FRONTEND\"" >> $CHROOT_VARIABLES
[ -n "$DEBOOTSTRAP" ] && echo "DEBOOTSTRAP=\"$DEBOOTSTRAP\"" >> $CHROOT_VARIABLES
[ -n "$EXTRAPACKAGES" ] && echo "EXTRAPACKAGES=\"$EXTRAPACKAGES\"" >> $CHROOT_VARIABLES