installation failure with current lenny packages

[Guido Günther <agx@sigxcpu.org>]

Hi,
while testing the multipath inststallation the current lenny installer +
the multipath patches posted to the bts fails like this during the
"install system" step (it prints "running preseed..." in the progress
bar dialog at this moment:

Mar  2 13:12:12 apt-install: Queueing package e2fsprogs for later installation
Mar  2 13:12:12 apt-install: Queueing package multipath-tools-boot for later installation
Mar  2 13:12:15 main-menu[1192]: INFO: Falling back to the package description for auto-install 
Mar  2 13:12:15 main-menu[1192]: INFO: Falling back to the package description for ai-choosers 
Mar  2 13:12:15 main-menu[1192]: INFO: Menu item 'live-installer' selected 
Mar  2 13:12:15 main-menu[1192]: INFO: Falling back to the package description for squashfs-modules-2.6.22-3-486-di 
Mar  2 13:12:15 main-menu[1192]: INFO: Falling back to the package description for squashfs-modules-2.6.22-3-486-di 
Mar  2 13:12:18 base-installer: chroot: cannot execute apt-get: No such file or directory
^^^^^^^^^

Mar  2 13:12:18 base-installer: warning: apt update failed: 1
Mar  2 13:12:18 in-target: Unexpected error; command not executed: 'sh -c debconf-apt-progress --no-progress --logstderr -- apt-get -o APT::Install-Recommends=false -q -y --no-remove install locales'
Mar  2 13:12:18 base-installer: /usr/lib/post-base-installer.d/05localechooser: 
Mar  2 13:12:18 base-installer: /usr/lib/post-base-installer.d/05localechooser: 49: 
Mar  2 13:12:18 base-installer: cannot create /target/etc/default/locale: Directory nonexistent
Mar  2 13:12:18 base-installer: warning: /usr/lib/post-base-installer.d/05localechooser returned error code 2
Mar  2 13:12:18 preseed: chroot: cannot execute debconf-set-selections: No such file or directory
Mar  2 13:12:19 base-installer: warning: /usr/lib/post-base-installer.d/05preseed returned error code 1
Mar  2 13:12:19 base-installer: warning: /usr/lib/post-base-installer.d/05tzsetup returned error code 10
Mar  2 13:12:19 main-menu[1192]: INFO: Priority changed externally, setting main-menu default to 'medium' (OK) 
Mar  2 13:12:19 main-menu[1192]: INFO: Menu item 'live-installer' succeeded but requested to be left unconfigured. 
Mar  2 13:12:19 main-menu[1192]: INFO: Modifying debconf priority limit from 'Incorrect number of arguments' to 'low' 
Mar  2 13:12:19 debconf: Setting debconf/priority to low

Any idea what causes this? When I select to install the Grub Bootloader
afterwards and then select "Install the system" form there things work
as expected. Any ideas?
 -- Guido