Example does not work

I tried to build the cube example, and get this error
```
thread 'main' panicked at 'GLFW Error: EGL: Failed to get EGL display: One or more argument values are invalid', /home/porky11/.cargo/registry/src/github.com-1ecc6299db9ec823/glfw-0.8.0/src/lib.rs:325
note: Run with `RUST_BACKTRACE=1` for a backtrace.
```

Start by reproducing the cube example and inspect the GLFW initialization path identified by the panic in glfw-0.8.0/src/lib.rs:325. Compare the example's environment and graphics setup with the EGL error; done means the cube example builds and runs without this panic.

Written by the indexing model from the issue text.