Q:

How to manually trigger DLTK indexing in Eclipse PDT for a PHP project

While developing in Eclipse with PDT (or Zend Studio), I frequently switch between different large branches using git--typically on the command line, not via a git plugin for eclipse.  Within seconds, Eclipse detects the branch switch and updates itself to reflect any file changes, then refreshes the project explorer and other views. 
However, the libraries on the different branches in the same project can be significantly different.   Frequently when switching branches,  a class is used in the new branch that doesn't exist in the earlier one which was indexed, Eclipse will show yellow warning about a class not being found in files using the new classes.   
This is not valid, and if I make a change (like add a space) then save the file with the missing class warning, the warning goes away--clearly this shows eclipse can find the referenced class. 
Is there any way to trigger/force DLTK indexing in PDT to run?   I'm assuming this is the issue at the root of my bogus warnings. 

A:

Project -> Clean -> Select project name -> OK

