mount dev, proc, sys in a chroot environment?

The Arch Linux Wiki suggests the following commands:

cd /mnt/arch # or where you are preparing the chroot dir
mount -t proc /proc proc/
mount --rbind /sys sys/
mount --rbind /dev dev/

For /proc and /sys, I suppose you could use either method. They are both special file systems so they can be recreated any number of times (the bind mount method uses the exact same mount as the host system, whereas the other method uses a new mount). I've always seen the bind mount recommended in guides, so I'd use that. As far as I know, there is no real important difference.

However, /dev is usually a tmpfs mount that is managed by udev, so it has to be the actual same file system as on the host machine. That means that you would need to use the bind mount method.

If this chroot is going to be around for awhile, you can put these entries in /etc/fstab on the host system to simplify things.

The Gentoo Handbook specifically calls out these two commands for re-mounting /proc and /dev. I've used them several times.

mount -t proc none /mnt/chroot/proc
mount -o bind /dev /mnt/chroot/dev

I suspect /sys is just a regular folder, so you should be able to make a hard link.

ln /sys /mnt/chroot/sys