From now on, when reentering the chroot environment after exiting, use the following modified chroot command:
chroot "$LFS" /usr/bin/env -i \ HOME=/root TERM="$TERM" PS1='\u:\w\$ ' \ PATH=/bin:/usr/bin:/sbin:/usr/sbin \ /bin/bash --login
The reason for this is that the programs in /tools are no longer needed. Since they are no longer needed you can delete the /tools directory if so desired.
Removing /tools will also remove the temporary copies of Tcl, Expect, and DejaGNU which were used for running the toolchain tests. If you need these programs later on, they will need to be recompiled and re-installed. The BLFS book has instructions for this (see http://www.linuxfromscratch.org/blfs/).
If the virtual kernel file systems have been unmounted, either manually or through a reboot, ensure that the virtual kernel file systems are mounted when reentering the chroot. This process was explained in Section 6.2.2, “Mounting and Populating /dev” and Section 6.2.3, “Mounting Virtual Kernel File Systems”.