title: Can't get rid of "Changes not staged for commit'
body: <p>I am unable to get rid of this state in which my repo is seem to be locked in. After a doing a reset to HEAD~1, I keep getting this notification about this single file being modified. 'add' and 'checkout' have not affect. I have core.autocrlf and core.safecrlf unset (empty).</p>
  
  <p>Please see below:</p>
  
  <pre><code>$ git --version
  git version 1.7.9.6 (Apple Git-31.1)
  
  $ git status
  
  # Changes not staged for commit:
  #   (use "git add &lt;file&gt;..." to update what will be committed)
  #   (use "git checkout -- &lt;file&gt;..." to discard changes in working directory)
  #
  #       modified:   a_file_name.cpp
  </code></pre>
  
  <p>The followings commands (ran individually) have no affect:</p>
  
  <pre><code>$ git checkout -- a_file_name.cpp
  $ git reset a_file_name.cpp
  $ git add a_file_name.cpp
  $ git reset --hard
  $ git clean -n
  &lt;nothing&gt;
  $ git clean -f
  &lt;nothing&gt;
  
  $ git status
  
  # Changes not staged for commit:
  #   (use "git add &lt;file&gt;..." to update what will be committed)
  #   (use "git checkout -- &lt;file&gt;..." to discard changes in working directory)
  #
  #       modified:   a_file_name.cpp
  </code></pre>
  
  <p>and it goes on ...</p>
  
  <h2>What did I do wrong?</h2>
  
  <p>Response to @Don's suggestion below (git rm), no change, but here is how it goes:</p>
  
  <pre><code>$ git rm 
  error: 'a_file_name.cpp' has local modifications
  (use --cached to keep the file, or -f to force removal)
  $ git rm -f a_file_name.cpp
  rm 'a_file_name.cpp'
  $ git status
  
  # Changes to be committed:
  #   (use "git reset HEAD &lt;file&gt;..." to unstage)
  #
  #       deleted:    a_file_name.cpp
  #
  # Changes not staged for commit:
  #   (use "git add/rm &lt;file&gt;..." to update what will be committed)
  #   (use "git checkout -- &lt;file&gt;..." to discard changes in working directory)
  #
  #       deleted:    a_file_name.cpp
  #
  
  $ git commit -m"tmp"
  [master 2a9e054] tmp
  1 file changed, 174 deletions(-)
  delete mode 100644 a_file_name.cpp
  
  $ git status
  # Your branch is ahead of 'origin/master' by 1 commit.
  #
  # Changes not staged for commit:
  #   (use "git add/rm &lt;file&gt;..." to update what will be committed)
  #   (use "git checkout -- &lt;file&gt;..." to discard changes in working directory)
  #
  #       deleted:    a_file_name.cpp
  #
  </code></pre>
  
  <p>Pretty much back to sq.1</p>