title: Cygwin & Python: pip install <package> cause error "Files/directories not found in"
body: <p>Running under Cygwin, I attempt the following:</p>
  
  <pre><code>$ pip install --no-cache-dir ibm_db
  Collecting ibm_db
    Downloading https://files.pythonhosted.org/packages/3f/61/389c6decacfed61c2724005b8c2be61f2c699f731b53af13517e5a0e6e98/ibm_db-2.0.9.tar.gz (782kB)
      100% |████████████████████████████████| 788kB 2.6MB/s
  Files/directories not found in /tmp/pip-install-aaq0fljf/ibm-db/pip-egg-info
  $
  </code></pre>
  
  <p>Always under Cygwin, I successfully install other packages with pip.  This same package installs successfully under Linux.  Thus why is this particular package incompatible with Cygwin?  What can be the cause of the error?</p>
  
  <p>Version of Python:  Python 3.6.4 (default, Jan  7 2018, 15:53:53)</p>