title: Homebrew recompile from edited source code
body: <p>Is there a way to to recompile from an edited source code via homebrew? </p>
  
  <p>I did a change on the source user.hpp of Boost which I now want to recompile Boost with. I tried <code>--build-from-source</code> and <code>--enable-bar</code> but neither works, saying that it is already installed. The only way I can recompile is by reinstall but that simply overwrites the source code I changed.</p>
  
  <p>Any idea?</p>