title: Git - error: Unable to append to .git/logs/refs/heads/bugfix_artfXX
body: <p>I have created a branch to work on a bug fix and when done with my changes tried to commit but got following error:</p>
  
  <pre><code>git commit -a -m "."
  error: Unable to append to .git/logs/refs/heads/bugfix_artfXX
  fatal: cannot update HEAD ref
  </code></pre>
  
  <p>I read posts in <a href="https://stackoverflow.com/">stack-overflow</a> and other websites pointing to the same problem and they mostly are fixed by fixing permissions. I tried to change to full permission on .git directory and all sub-directories but did not help.</p>
  
  <p>What's strange to me is that I was able to commit until yesterday but today I get this annoying message.</p>