```ruby
#require 'rack/jekyll'
require 'bundler/setup'
Bundler.require(:default)

run Rack::Jekyll.new(:destination => '_site')
```

Remove needless destination option in Jekyll.new
user
```ruby
#require 'rack/jekyll'
require 'bundler/setup'
Bundler.require(:default)

run Rack::Jekyll.new
```
assistant