Can't install in chroot because /proc is not mounted

Description: Ubuntu 9.04
Release: 9.04

When installing this package inside our netboot tree, the following happens:

(Reading database ... 367010 files and directories currently installed.)
Preparing to replace libndesk-dbus-glib1.0-cil 0.4.1-1ubuntu1 (using .../libndesk-dbus-glib1.0-cil_0.4.1-1ubuntu1_all.deb) ...
Removing libndesk-dbus-glib1.0-cil from Mono
W: removing assembly: Mono requires /proc to be mounted. failed!
Unpacking replacement libndesk-dbus-glib1.0-cil ...
Preparing to replace libndesk-dbus1.0-cil 0.6.0-1ubuntu1 (using .../libndesk-dbus1.0-cil_0.6.0-1ubuntu1_all.deb) ...
Removing libndesk-dbus1.0-cil from Mono
W: removing assembly: Mono requires /proc to be mounted. failed!
Unpacking replacement libndesk-dbus1.0-cil ...
Can not write log, openpty() failed (/dev/pts not mounted?)
Setting up libndesk-dbus1.0-cil (0.6.0-1ubuntu1) ...
* Installing 1 assembly from libndesk-dbus1.0-cil into Mono
E: installing Assembly /usr/lib/cli/ndesk-dbus-1.0/NDesk.DBus.dll failed

Setting up libndesk-dbus-glib1.0-cil (0.4.1-1ubuntu1) ...
* Installing 1 assembly from libndesk-dbus-glib1.0-cil into Mono
E: installing Assembly /usr/lib/cli/ndesk-dbus-glib-1.0/NDesk.DBus.GLib.dll failed

This in fact hinders *any* installation of mono packages inside a chroot. Mounting /proc is no option, as this might interfere with the running system (we have Debian Etch Servers providing the netboot-roots for ubuntu hardy and jaunty clients and have had some pretty bad experiences while installing packages with /proc mounted inside the chroot).

Sorry for the briefness of this report but I believe you get the picture.

Lukas