title: Git clone with custom SSH using GIT_SSH error
body: <p>I am trying to clone a Git repo using a custom SSH command. I set the SSH command in the GIT_SSH environmental variably be running </p>
  
  <p><code>export GIT_SSH="/usr/bin/ssh -o StrictHostKeyChecking=no -i /home/me/my_private_key"</code>. </p>
  
  <p>But when, after the previous command I run </p>
  
  <p><code>git clone git@bitbucket.org:uname/test-git-repo.git</code>, I get the following weird error</p>
  
  <pre><code>error: cannot run /usr/bin/ssh -o StrictHostKeyChecking=no -i /home/me/my_private_key
  fatal: unable to fork
  </code></pre>
  
  <p>Can you please help me out solve this issue?</p>