uck 2.4.3 doesn't respect http_proxy variable

crypt@sympho ~ $ echo $http_proxy
http://localhost:3000

crypt@sympho ~ $ cat /home/crypt/tmp/build.log
Build (/usr/bin/uck-gui ) started at 2011-04-27 18:57:09
Ubuntu Customization Kit 2.4.3
Starting CD remastering on Wed Apr 27 18:57:09 NOVST 2011
Customization dir=/home/crypt/tmp/customization-scripts
Mounting ISO image...
Unpacking ISO image...
Unmounting ISO image...
Mounting SquashFS image...
Unpacking SquashFS image...
Unmounting SquashFS image...
Removing win32 files...
Creating apt cache...
Creating root home...
Mounting /proc
Mounting /sys
Mounting /dev/pts
Mounting /var/run
Mounting /tmp
Mounting /home/crypt/tmp/remaster-root-home
Mounting /home/crypt/tmp/remaster-apt-cache
Mounting /home/crypt/tmp/customization-scripts
Copying resolv.conf...
Copying fstab/mtab...
Creating DBUS uuid...
Creating user directory...
Copying X authorization file to chroot filesystem...
xauth: creating new authority file /root/.Xauthority
xauth: creating new authority file /home/crypt/.Xauthority
Deactivating initctl...
Deactivating update-grub...
Remembering kernel update state...
Err http://security.ubuntu.com lucid-security Release.gpg
  Something wicked happened resolving 'localhost:3000' (-5 - No address associated with hostname)
Err http://archive.ubuntu.com lucid Release.gpg
  Something wicked happened resolving 'localhost:3000' (-5 - No address associated with hostname)
Err http://archive.ubuntu.com lucid-updates Release.gpg

... etc...