title: Failed to create a new branch from upstream
body: <p>I wanted to create a new branch from upstream. What I did are</p>
  
  <pre><code>$ git init
  $ git clone https://github.com/nalam-nmef/LearnGitWithGithubFlow.git
  $ git remote add upstream https://github.com/twentyTwo/LearnGitWithGithubFlow.git
  </code></pre>
  
  <p>then, to create a new branch from upstream</p>
  
  <pre><code>$ git checkout -b changes1 upstream/master
  </code></pre>
  
  <p>But in this point an error occurs. It says</p>
  
  <blockquote>
    <p>fatal: Cannot update paths and switch to branch 'changes1' at the same
    time. Did you intend to checkout 'upstream/master' which can not be
    resolved as commit?</p>
  </blockquote>
  
  <p>What I will do after that is pushing that new branch to my fork</p>
  
  <pre><code>$ git push -u origin changes1
  </code></pre>
  
  <p>That is, I always create a branch for a new change request locally. The branch is created from the upstream/master branch. Commit changes locally and push it to my fork. Then, create a pull request to the upstream master. But, I am getting the error in <code>$ git checkout -b changes1 upstream/master</code></p>
  
  <p>Whats the wrong with this? What is the best practice?</p>