Mounting $LFS/proc file system
In order for certain programs to function properly the proc file system
must be mounted and available from within the chroot'ed environment as
well. It's not a problem to mount the proc file system twice
or even more than that, since it's a virtual file system maintained by
the kernel itself.
The proc file system is mounted under $LFS/proc by running the following command:
mount proc $LFS/proc -t proc