title: Teamcity fails to merge automatically
body: <p>Given there are <strong>master</strong> and <strong>dev</strong> git branches, a git repository is hosted on the Github and TeamCity 9.0.1 installed as a CI server.</p>
  
  <p>The teamcity build project is configured to use github repository as a VCS root with <strong>refs/heads/master</strong> set as a default branch.</p>
  
  <p>The desired behavior is to run auto-merge from <strong>master</strong> to <strong>dev</strong> when the build is successful.</p>
  
  <p>So I add an <strong>Automatic merge</strong> build feature as specified <a href="https://confluence.jetbrains.com/display/TCD9/Automatic+Merge" rel="noreferrer">here</a> with the following settings: </p>
  
  <ul>
  <li>Watch builds in branches => Branch filter: <code>+:master</code></li>
  <li>Merge into branch: <code>dev</code></li>
  <li>Merge commit message: <code>TEAMCITY: Automatic merge branch master into dev</code></li>
  <li>Perform merge if: <code>build is successful</code></li>
  <li>Merge policy: <code>use fast-forward merge if possible</code></li>
  </ul>
  
  <p>After pressing Run - the build is green, no errors are shown in the Build Log, but totally nothing was merged as desired!</p>
  
  <p>What's wrong and where can I find the debug information about build features execution?</p>