I came over the error:
Reading package lists... Done
W: GPG error: http://ftp.no.debian.org lenny Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY AED4B06F473041FA
W: You may want to run apt-get update to correct these problems
When running apt-get update .
The solution is actually to do a
apt-get install debian-archive-keyring
I got a rdesktop package from a specific ubuntu ppa repo that fixed a bug, the fix hasn’t made it into the official ubuntu repo for some unknown (to me) reason. I install my local package with dpkg but apt-get upgrade always upgrades that package and I have to do it all over. I remember pinning a package in Debian some years back, so I tried the same solution on my Ubuntu Natty setup.
joar@jupiter:~$ cat /etc/apt/preferences.d/rdesktop
Pin: version 1.6.0-2ubuntu3ppa1*
As you can see I created a /etc/apt/preferences.d/rdesktop preferences file, and now my apt-get upgrade leaves redesktop to the version I’ve installed with dpkg. 🙂
More info regarding pinning in :
$ man 5 apt_preferences