title: bitbake: how to add package depending on MACHINE?
body: <p>My images, built with <code>bitbake</code>, must contain different packages for different machines (say, I need to add package <code>package1</code> to image for <code>machine1</code>, but not for <code>machine2</code>).</p>
  
  <p>It is possible to add line</p>
  
  <pre><code>IMAGE_INSTALL_append_machine1 = " package1"
  </code></pre>
  
  <p>to the image recipe. But I do not think this is sustainable, as <code>IMAGE_INSTALL_append_machine1</code> may be defined in some other recipe (which is not under my control) and the earlier definition gets overwritten with the later one. This is what I think Yocto Project Development manual <a href="http://www.yoctoproject.org/docs/2.0/ref-manual/ref-manual.html#var-IMAGE_INSTALL" rel="noreferrer">warns about using IMAGE_INSTALL</a>.</p>
  
  <p>Is my concern valid? What is the proper way to write the recipe(s) in this case?</p>