I got that error building with these config:
$ LOCALOPTS=" --mirror-binary http://ftp.us.debian.org/debian/
--mirror-chroot http://ftp.us.debian.org/debian/ --mirror-bootstrap
http://ftp.us.debian.org/debian/ --mirror-binary-security
http://security.eu.debian.org/ --mirror-chroot-security
http://security.eu.debian.org"
$ lh_config --bootstrap-flavour minimal --apt apt --distribution squeeze
--union-filesystem unionfs --packages fluxbox xserver-xorg $LOCALOPTS
--
Regards,
Umarzuki Mochlis
http://gameornot.net