Adding user to chroot environment

I've created a chroot system in my Ubuntu using schroot and debrootstrap, based on minimal ubuntu. However whenever I can't seem to add a new user into this chroot environment. Here is what happens.

1. I enter schroot as root and add a new user 'Bob'.(Tried both adduser and useradd commands)
2. The username 'Bob' lists up in /etc/passwd file and I can 'su' into the user 'Bob'. So far so good.
3. When I log out of schroot, and re-enter schroot, the user 'Bob' has vanished!! There is no mention of Bob in /etc/passwd either.

How do I make the new user permanent?

Solution 1:

Oh well, I figured it out myself. schroot has a features called "sessions" that allows preservation of current system environment. I somehow thought that adding new users would not be a part of "environment".