title: What do double quotes signify in Xcode's search paths?
body: <p>Tonight we had an annoying issue that only presented itself in Xcode's command line builds, not from Xcode's GUI.</p>
  
  <p>When building from a machine with Xcode's GUI with a recursive User Header Search path of $PROJROOT, without double quotes, we experienced no issue. However, when building with Jenkins, which uses Xcode's command line build capability, errors were thrown that Headers were unfindable.</p>
  
  <p>After an hour of poking around, someone decided to try to wrap the recurive $PROJROOT in double quotes, ("$PROJROOT"). Once this happened, Jenkins command line building of the project was finally successful.</p>
  
  <p>So we don't fully understand the ramifications of wrapping our search paths in quotes, or omitting the quotes.</p>
  
  <p>Can anyone shed some light on what exactly was causing this issue? What double quotes signify to the compiler from the command line vs the GUI?</p>