To make this, you can do: 

```ruby
options.merge!({
  new_options
})
```

This way able you to do just:

```ruby
options = Jekyll.configurations(options.merge!({
  new_options
}))
```

And, personally, I do not like these multiple attributions to the same variable, further when the two attributions are of different kinds. I don't really understand why I do not like this, since this, for me, is a pretty nice feature of ruby language (the duck typing). Maybe some code addiction of mine, or maybe I've fear of what this can become.

In short, I'd do it this way:

```ruby
options = Jekyll.configurations(normalize_options(options.__hash__).merge!({
  new_options
}))
```