title: Buildrequiring a subpackage by another subpackage?
body: <p>I'm trying to build an RPM of Google's protobuf, including the protobuf-python subpackage. Now, this is no problem until i want to build the python subpackage with <code>PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=cpp python setup.py build</code>. This requires the protobuf header files and lib provided by the protobuf-devel package, which is built from the same .spec and source tarball.</p>
  
  <p>The question is, is it somehow possible to build the (-python) subpackge in such scenario using a single .spec &amp; tarball, or must i create a separate spec?</p>
  
  <p>Here's the <a href="http://mirror.chpc.utah.edu/pub/epel/beta/7/SRPMS/protobuf-2.5.0-6.el7.src.rpm" rel="nofollow">.src.rpm</a> if anyone is curious. All i did was to prepend the <code>PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=cpp</code> to <code>python setup.py build</code> command.</p>