title: Fixing MSVC Compiler Error C1074: Illegal extension
body: <p>Using Visual Studio 2003 Professional under Windows 7 SP1 (64 bit), compiling from the command line, I get a fatal error C1074: <code>IDB is illegal extension for PDB file</code>. The documentation on this error is <a href="http://msdn.microsoft.com/en-us/library/116s07h4%28v=vs.71%29.aspx" rel="nofollow">sparse</a> to put it lightly. The incredibly odd thing about this is that, utilizing the same build script on the same computer but under a different account does not generate this error. </p>
  
  <p>My first guess was that something in the environment variables is causing this conflict, but doing a diff between them for the two accounts, and modifying PATH and INCLUDE to be the same does not fix the error.</p>
  
  <p>Does anyone have a fix for this error, or any idea what actually triggers it? None of the files are being compiled with a <code>/Z</code> switch of any kind, so as far as I can tell, no <code>PDB</code> files should ever actually be generated (and on a successful build, no <code>IDB</code> OR <code>PDB</code> files are generated that I can see).</p>