title: In Azure DevOps Pipelines. How do you choose an alternate GitHub branch?
body: <p>B"H</p>
  
  <p>Simply. I'd like to build the code in a branch of my GitHub repo that is not master.
  I don't see any option to do that.
  It lets you choose which repo you want to checkout as the first step in a pipeline, but not which branch.</p>
  
  <p>I see that once you've created the pipeline. There is a file <code>azure-pipelines.yml</code> which has a line called trigger.
  However</p>
  
  <ol>
  <li>It's not only which branch I want to trigger the build. It's also that I want use the code from the second branch for this build</li>
  <li>It does not give you the option to save azure-pipelines.yml in any branch other than master (or one that it will create right then for you <strong>from master</strong>)</li>
  <li>Changing the branch listed under trigger doesn't actually work. (probably because of the first two issues). It still only triggers if check into master</li>
  </ol>
  
  <p>So how would I choose an alternate branch.
  Thank you.</p>