The Piston core is now 0.5 and includes some breaking changes:

  • The event crate is merged with the input crate
  • The event_loop is reexported as a module under piston

If you are using Piston-Window these changes will not have much effects.

To fix your code, replace use piston::event::*; with use piston::input::*;.

The motivation for this change is to make it easier to maintain generic libraries by depending on pistoncore-input only. In many cases you do not need a window abstraction to share code between projects. Such libraries include controllers, AI and UI.