title: How to exclude specific directories for dist-gzip / dist-zip?
body: <p><strong>Background</strong>:
  Automake provides different <a href="https://www.gnu.org/software/automake/manual/html_node/The-Types-of-Distributions.html" rel="nofollow">types of distributions</a>. After reading the docs "<a href="https://ftp.gnu.org/old-gnu/Manuals/automake-1.6.1/html_chapter/automake_15.html" rel="nofollow">What Goes in a Distribution</a>" I know how to <em>include</em> extra directories <em>in general</em>. But I'm not sure about the best way to <em>exclude</em> directories in this list <em>for a single rule</em>.</p>
  
  <p>This is the part in current <code>configure.ac</code> that adds to the dist directories</p>
  
  <pre><code>AC_CONFIG_MACRO_DIR([m4])
  AC_CONFIG_AUX_DIR([build_aux])
  </code></pre>
  
  <p>And this is the part in current <code>Makefile.am</code> that adds to the dist directories</p>
  
  <pre><code>SUBDIRS = sources po doc tests
  EXTRA_DIST = build_windows
  </code></pre>
  
  <p>Furthermore <code>Makefile.am</code> has</p>
  
  <pre><code>AUTOMAKE_OPTIONS = dist-zip
  </code></pre>
  
  <p>For enabling the zip distribution.</p>
  
  <p><strong>Result</strong>: both <code>package.tar.gz</code> and <code>package.zip</code> have the same content. Therefore the following directories are included:</p>
  
  <ul>
  <li>build_aux</li>
  <li>build_windows</li>
  <li>doc</li>
  <li>m4</li>
  <li>po</li>
  <li>sources</li>
  <li>tests</li>
  </ul>
  
  <p><strong>Question</strong>:
  How to <strong>exclude</strong> <code>build_windows</code> in <code>package.tar.gz</code> and <code>m4</code> in <code>package.zip</code>?</p>