could not chroot with debootstrap

[Umarzuki Mochlis <umarzuki@gmail.com>]

i'm trying to create a 64-bit environment on my debian lenny 32-bit to create a 64-bit deb package

the command i'm using is:

# debootstrap --arch=amd64 lenny lenny64/ http://ftp.us.debian.org/debian/

failure message:

W: Failure trying to run: chroot /home/umarzuki/lenny64 mount -t proc proc /proc

what is wrong with the command

--
Regards,

Umarzuki Mochlis
http://debmal.my