title: How to recompile modifications to VCL source file (Menus.pas)?
body: <p>We have a modified menus.pas.</p>
  
  <p>At </p>
  
  <pre><code>uses ...,Controls,...;
  </code></pre>
  
  <p>The compiler raised a fatal error:</p>
  
  <blockquote>
    <p>[DCC Fatal Error] Menus.pas(*): F2051 Unit Controls was compiled with
    a different version of Menus.TPopupMenu</p>
  </blockquote>
  
  <p>tried:</p>
  
  <p>deleted all dcu in the project.</p>
  
  <p>build </p>
  
  <p>build all</p>
  
  <p>tried adding the file to library path which leads to add db folder(from vcl too) and then to </p>
  
  <blockquote>
    <p>[DCC Error] jpeg.pas(872): E2065 Unsatisfied forward or external declaration: 'jpeg_save_markers'</p>
  </blockquote>
  
  <p>which is a dead end.</p>
  
  <p>deleted the controls.dcu (all 3) and the delphi did not know automaticaly to recompile them, instead reported that controls.dcu is missing.</p>