apt-get update: Clearsigned file is not valid, got 'NODATA'

Question

I'm getting the following error on running sudo apt-get update :

sudo apt-get update                                                                
Get:1 http://dl.google.com stable InRelease
100% [1 InRelease gpgv 3,435 B] [Connecting to in.archive.ubuntu.com] [ConnectiSplitting up /var/lib/apt/lists/partial/dl.google.com_linux_talkplugin_deb_dists_stable_InReleaseIgn http://dl.google.com stable InRelease                                      
E: GPG error: http://dl.google.com stable InRelease: Clearsigned file isn't valid, got 'NODATA' (does the network require authentication?)

I tried:

$ cd /var/lib/apt
$ sudo mv lists lists.old
$ sudo mkdir -p lists/partial
$ sudo apt-get update

But still getting the same error. Never faced this problem before. I was trying to install texlive-full and ran out of space during installation, apt-get install wasn't working then and gave the following output:

E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem.

As per the answer here: Message 'E:dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem.' I tried:

cd /var/lib/dpkg/updates
sudo rm *
sudo apt-get update

And then this error occured. Now apt-get install is working fine but update isn't working. What is the solution?

Solution

On a hunch, I changed all references to http://dl.google.com to https://dl.google.com and it started to work. I think Google has shut down all their vanilla http ports and the just do a redirect to https. But apt and dpkg don't follow the redirects so they fail with 'NODATA' message.

Comments

[Nitin Labhishetty]

I tried sudo dpkg --configure -a. It runs, gives no output though. sudo apt-get -f install says all packages up to date. But sudo apt-get update gives the above error. Is this because some link might be blocked by network admin? Many sites are blocked in my college.