Development Team/Chroot

Sugar ought to be easy to run from chroots. For a variety of silly reasons, this isn't yet the case, but it might be soon. Ping Michael with questions.

Chroot Construction

There are lots of ways to create appropriate chroots; e.g. by hand, with debootstrap, with mock, etc.

With debootstrap, in order to get a working chroot you want something like:

 export CHROOT=`pwd`/sid-root
 debootstrap --arch i386 sid $CHROOT http://debian.lcs.mit.edu/debian
 sudo chroot $CHROOT /bin/bash -l
 # and some of the following:
 mount -t proc proc $CHROOT/proc
 mount -t devpts devpts $CHROOT/dev/pts
 mount -t selinuxfs selinux $CHROOT/selinux

With mock, it would be more like:

 mock -r fedora-devel-i386 --init
 mock -r fedora-devel-i386 --shell

X11

Most X11 servers are configured to disable TCP connections. This means that in order to get a working X connection we can:

1. bind-mount the X unix socket into the chroot.
2. ssh into the chroot with X11-forwarding enabled.
3. enable TCP on an X server, e.g. a nested Xephyr.

We're going to try option (3) first:

 Xephyr -ac :1

NB: If you figure out how to make Xephyr bind only to localhost sockets (or how to make it use a custom xauth config), speak up!

and, inside the chroot:

 export DISPLAY=localhost:1

D-Bus

Sugar wants to be able to use global state stored in both HAL and NetworkManager, both of which live on the system bus. Consequently, we need to bind-mount

 mount --bind /var/run/dbus $CHROOT/var/run/dbus

before entering the chroot. (Mock uses unshare() to enter a new mount-point namespace since this makes garbage collection of mountpoints much easier.)