1. Save the script which adds the keys for all your PPA repos:

2. Chmod the script to 775. To do this, navigate to where the script was extracted and paste this in a terminal:

chmod 775 launchpad-update

3. Create a new file, " /etc/apt/apt.conf.d/05ppa " (file 05ppa which should be located in /etc/apt/apt.conf.d ) and put this in it:



APT::Update::Pre-Invoke { "if [ -x /usr/local/bin/launchpad-update ]; then /usr/local/bin/launchpad-update; fi"; };



This will help you get rid of errors such as:

W: GPG error: http://ppa.launchpad.net jaunty Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 5A9BF3BB4E5E17B5

W: GPG error: http://ppa.launchpad.net jaunty Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 3B22AB97AF1CDFA9

W: You may want to run apt-get update to correct these problems This will help you get rid of errors such as:

Some time ago we wrote about a script to automatically install launchpad PPA GPG keys for all your repositories but you needed to run that script each time you would add a new PPA repository. But now thanks to a SourceGuru tip, you can have this script run automatically each time you do an update (apt-get update). Download it , extract and put it in /usr/local/bin (or any other place, it's just an example but if you don't place it there, be sure to also modify the path in the next steps).