Mounting /proc file system
In order for certain programs to function properly, the proc file
system must be available from within the chroot'ed environment.
A file system can be mounted as many times and in as many places
as you'd like, so it's not a problem that the proc file system is already
mounted on your host system, especially so because proc is a
virtual file system.
The proc file system is mounted under /proc by running the
following command.
mount proc /proc -t proc