Spock & Spock Reports: How print a variable valuable in Label/Block

I am working with:

• Spock Core
• Spock Reports
• Spock Spring
• Spring MVC Testing

and I have the following code:

def "findAll() Expected"(){

    given: "The URL being used is: /personas/xml/personas"

        url = PersonaUrlHelper.FINDALL;

    when: "When the URL is being calling with a GET"

        resultActions = mockMvc.perform(get(url)).andDo(print())

    then: "something..."

        resultActions.andExpect(status().isOk())
                     .andExpect(content().contentType(RequestMappingProducesJsonUtf8.PRODUCES_JSON_UTF_8))

}

Two observations:

One: observe given: "The URL being used is: /personas/xml/personas" where the URL/URI value has been added manually.

Two: the url variable has been defined how an instance variable, because it is common in many test methods. Therefore def String url

My question is:

how I can display the url variable in a Spock's label/block? how (given, then…)? It to be printed through Spock Reports and improve my testing documentation

I have read the following: Spocklight: Extra Data Variables for Unroll Description

It working around @Unroll. But I did realize all work around the where label/block.

I already have tried something like:

given: "The URL being used is: $url"
given: "The URL being used is: ${url}"

And does not work

I want to work around with a syntax similar like the following:

def "findAll() Expected"(){

    url = PersonaUrlHelper.FINDALL;

    given: "The URL being used is: $url"

        …. something

    when: "When the URL is being calling with a GET"

So what could be the correct configuration?

Asume I do a refactor for PersonaUrlHelper.FINDALL used in some Spring's @RequestMapping and in this test method. I don't want update manually the text in the given label/block

So what is the correct syntax?