title: git rm --cached and fatal: pathspec
body: <p>I just tried to checkout my master branch and ran into:</p>
  
  <pre><code>error: Untracked working tree file 'app.xcodeproj/project.xcworkspace/xcuserdata/u.xcuserdatad/UserInterfaceState.xcuserstate' would be overwritten by merge. 
  </code></pre>
  
  <p>So, I tried to delete this file from git (I'd already added an expression in .gitignore to catch it) using:</p>
  
  <pre><code>git rm --cached app.xcodeproj/project.xcworkspace/xcuserdata/u.xcuserdatad/UserInterfaceState.xcuserstate
  </code></pre>
  
  <p>and got:</p>
  
  <pre><code>fatal: pathspec 'app.xcodeproj/project.xcworkspace/xcuserdata/u.xcuserdatad/UserInterfaceState.xcuserstate' did not match any files 
  </code></pre>
  
  <p>So, at a bit of a loss. From my understanding the working file isn't the issue here. However, for completeness, a working file does exist. E.g. </p>
  
  <pre><code>ls -l app.xcodeproj/project.xcworkspace/xcuserdata/u.xcuserdatad/UserInterfaceState.xcuserstate
  -rw-r--r--  1 u  u  56061 24 Sep 12:42 app.xcodeproj/project.xcworkspace/xcuserdata/u.xcuserdatad/UserInterfaceState.xcuserstate
  </code></pre>