Error code E0758

A multi-line (doc-)comment is unterminated.

Erroneous code example:

#![allow(unused)] fn main() { /* I am not terminated! }

The same goes for doc comments:

#![allow(unused)] fn main() { /*! I am not terminated! }

You need to end your multi-line comment with */ in order to fix this error:

#![allow(unused)] fn main() { /* I am terminated! */ /*! I am also terminated! */ }