title: Eclipse: Switching between build configurations doesn't update excluded files
body: <p>I have two c++ source files. I am building each in a separate build configuration. I have set up each build configuration to exclude the other source file. In the Project Explorer, one of the file's icons has a slash through it, showing it as the source file that is excluded and I cannot refactor code for this source file. This is all as expected, done according to the <a href="https://stackoverflow.com/questions/2424795/building-multiple-binaries-within-one-eclipse-project">instructions found here</a>.</p>
  
  <p>I have verified that each file has the "Exclude resource from build" box checked for the appropriate build configuration. Furthermore, I have verified that the build command for each build configuration builds the correct source file.</p>
  
  <p>Then I click Project->Build Configurations->Set Active and select the other build configuration but the same source file is excluded. I also tried switching configurations by actually building the different configurations, but again, the file exclusions remain the same (both the icon shows it as deactivated and I cannot refactor that source file).</p>
  
  <p>I have searched various posts but do not see the exact circumstance I'm facing, though <a href="https://www.eclipse.org/forums/index.php/t/65971/" rel="nofollow noreferrer">this one was close</a>. Perhaps I don't know the correct terminology to do a proper search.</p>
  
  <p>Am I switching between configurations correctly? Is there a workaround for this behavior (besides including all files in the build, if I need to refactor, and then re-excluding them before build)?</p>
  
  <p>I have seen this behavior in Nsight (running Eclipse 3.8) and in Eclipse Mars (4.5.0). I am running on Linux CentOS 6.7, 64-bit.</p>