Local p2 mirrors to work offline

Working with Tycho without an internet connection?
=> Make a local mirror of the p2 repositories.

I was asked to create a maven tycho build for an existing scout application in a company where it was difficult to reach the eclipse repositories. Do not ask me why, I guess this has something to do with proxy, firewalls and so on…

This was really frustrating because I could see the plugins in my target editor, but during the maven build there was a lot of warnings that maven will contact another mirror and finally I got some timeout errors.