Today “sudo apt-get install python-dev” started failing with
"Err http://archive.ubuntu.com/ubuntu/ trusty-updates/main libpython2.7-dev amd64 2.7.6-8ubuntu0.2
404 Not Found [IP: 22.214.171.124 80]"
The same is happening for my students in their projects and after multiple retries.
UPDATE: was solved by tom’s fix to call sudo apt-get update before calling sudo apt-get install python-dev.