If you follow the instructions in the Citrix Developer Network to set up a (paravirtualized) Debian Lenny guest system apt-get or aptitude will show the following error
W: GPG error: http://updates.vmd.citrix.com lenny Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 841D6D8DFE3F8BB2 W: You may want to run apt-get update to correct these problems |
until you add the GPG key for the xen sources (defined in /etc/apt/sources.list.d/citrix.list):
# wget -q http://updates.vmd.citrix.com/XenServer/5.6.0/GPG-KEY -O- | apt-key add - |