title: Exclude manylinux wheels when downloading from pip
body: <p>At $company we run an internal pypi server to shield ourselves from public pypi downtime.  We also build wheels to avoid installation overhead for binary packages.  One common task is to import packages from public pypi which essentially boils down to:</p>
  
  <pre><code>pip install --download . --no-binary :all: $PACKAGE  # download a source distribution
  </code></pre>
  
  <p>and</p>
  
  <pre><code>pip wheel $PACKAGE  # build a binary distribution (or use a cached version that's already on our internal pypi)
  </code></pre>
  
  <p>Under the latest pip, this may download / install <code>manylinux</code> wheels during the <code>pip wheel</code> phase.  Due to bundling .so files <em>inside</em> the wheel, these are incompatible with our security requirements at $company.  How can we continue the same workflow while avoiding the manylinux wheels?</p>
  
  <p>Currently we're downgrading to <code>pip&lt;8</code>, but this seems non-ideal</p>