title: GString inside a Gstring in gradle/groovy
body: <p>I need to use a variable as a part of a string that will be used to address another variable in a gstring.<br>
  In syntesys, what I'd like to do is: <code>${${it}_checkout}</code></p>
  
  <p>The whole code line would be:<br>
  <code>def checkouts = repos.collect{"${it} = ${${it}_checkout} "}</code>  </p>
  
  <p>With <code>repos</code> being a list of repositories to checkout.<br>
  Each repo has an property called <code>&lt;repo&gt;_checkout</code>.</p>
  
  <p>For instance, if I have two repos, called <code>foo</code> and <code>bar</code>, I'll have two variables called <code>foo_checkout</code> and <code>bar_checkout</code>, containing the branches to be checkouted.<br>
  I'm trying to construct the following string: "foo=$foo_checkout bar=$bar_checkout".<br>
  That will be translated to "foo=master bar=dev"</p>
  
  <p>Is there a way ?</p>