will squid-deb-proxy be used for release upgrades?

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http://askubuntu.com – I am in the process of updating a bunch of machines to 12.xx. For regular package updates I tried apt-proxy, which had random hiccups (clients hanging on various headers). Now I installed apt-cacher-ng, but that seems not to work when running do-release-upgrade (I'm guessing because the special update-info does not match some URL pattern of apt-cacher-ng): user@machine:~# sudo do-release-upgrade --proposed Checking for a new ubuntu release Failed Upgrade tool signature Done Upgrade tool Done downloading authenticate 'lucid.tar.gz' against 'lucid.tar.gz.gpg' exception from gpg: GnuPG exited n (HowTos)