apt update hangs after "Hit:4 http:/...InRelease"

[ptomblin]

I upgraded from 15.10 to 16.04 this afternoon. This evening I notice that whenever I try
apt-get update or
apt update it hangs after

Hit:1 http://us.archive.ubuntu.com/ubuntu xenial InRelease
Hit:2 http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease
Hit:3 http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease
Hit:4 http://security.ubuntu.com/ubuntu xenial-security InRelease


I removed the third party sources from /etc/apt/sources.list.d

I swear this was working before I left for dinner.

[Brandon_MacEachern]

Somethings wrong on the server. Entire rack at work, all new machines just unboxed, are doing the same exact thing.

[The Cog]

http://gb.archive.ubuntu.com/ubuntu gives me the same problem. So it's not just a US server, it's something that's been rolled out to the repository mirrors too.
See this thread for a work-round: http://ubuntuforums.org/showthread.php?t=2325168