title: ldconfig seems no functional under alpine 3.3
body: <p>I'm currently install the goczmq (<a href="https://github.com/zeromq/goczmq" rel="noreferrer">https://github.com/zeromq/goczmq</a>) on golang:1.6.2-alpine docker container, as following:</p>
  
  <pre><code>wget https://download.libsodium.org/libsodium/releases/libsodium-1.0.10.tar.gz
  wget https://download.libsodium.org/libsodium/releases/libsodium-1.0.10.tar.gz.sig
  wget https://download.libsodium.org/jedi.gpg.asc
  gpg --import jedi.gpg.asc
  gpg --verify libsodium-1.0.10.tar.gz.sig libsodium-1.0.10.tar.gz
  tar zxvf libsodium-1.0.10.tar.gz
  cd libsodium-1.010.
  ./configure; make check
  sudo make install
  sudo ldconfig
  </code></pre>
  
  <p>The process failed on <code>ldconfig</code>, there seems be a command <code>ldconfig</code>, but  I don't think it is actually functional. Any insights? Thank you in advance. </p>