title: No usable M4 in $PATH or /usr5bin
body: <p>As part of a long, sordid story whose end goal is simply to get GMP installed for use with code::blocks in Windows, I am trying to configure gmp. I do this with the following command:</p>
  
  <blockquote>
    <p>./configure --prefix=${gmp_install}</p>
  </blockquote>
  
  <p>Everything starts out well enough. After a few minutes and a bit of progress, everything grinds to a halt and I get this message:</p>
  
  <blockquote>
    <p>configure: error: No usable M4 in $PATH or /usr5bin</p>
  </blockquote>
  
  <p>I don't even know what M4 is, but I discover that it is some sort of macro processor. So I download it, and add the folder to my Path variable. Then I start the configure again, but same result.</p>
  
  <p>Is there something that I need to do to M4 to get it working? I'm truly at a loss. Thanks for your help.</p>