[dureuill]

`let` defines a new binding, as opposed to changing the value of an existing binding. You can't remove `let` to keep only `=` because it has a different use case.

Not indicating the type is idiomatic in Rust, but you can annotate it:

    let commit_message: String = repo.head().peel_to_commit().ok()?.message()?.into();

Here this is useful to specify the type `into` should convert to. However, if rewritten as:

    let commit_message = repo.head().peel_to_commit().ok()?.message()?.to_string();

Then it is useless because we're already specifying the type of the variable by using `to_string`.

Note that IDEs are displaying type hints anyway (without you having to type them), so you don't have to suffer if walking through a codebase where people are annotating their types too little for comfort