title: Git : fatal: Ambiguous object name: 'origin/release_2.6'
body: <p>I am getting this error when trying to create a remote tracking branch</p>
  
  <pre><code>git co -b release_2.6 origin/release_2.6
  warning: refname 'origin/release_2.6' is ambiguous.
  warning: refname 'origin/release_2.6' is ambiguous.
  fatal: Ambiguous object name: 'origin/release_2.6'.
  </code></pre>
  
  <p>I only have these two refs defined with release_2.6</p>
  
  <pre><code>git show-ref | grep "release_2.6"
  a71b2da1526f73862464a23aceaa1939a8b1ace2 refs/heads/origin/release_2.6
  ed1399936a8cc4cd2feed1851123af861b0ff093 refs/remotes/origin/release_2.6
  </code></pre>
  
  <p>Does anyone know what this error means?</p>
  
  <p>Cheers</p>