title: unknown syscall.SysProcAttr field 'Unshareflags'
body: <p>I was trying out the Syscall in Go and had created the struct</p>
  
  <pre><code>cmd.SysProcAttr = &amp;syscall.SysProcAttr{
          //New UTS              Child become 1          Mount Name Space
          Cloneflags:   syscall.CLONE_NEWUTS | syscall.CLONE_NEWPID | syscall.CLONE_NEWNS,
          Unshareflags: syscall.CLONE_NEWNS, //Dont share the container to the host,
      }
  </code></pre>
  
  <p>but I get the error :</p>
  
  <pre><code>unknown syscall.SysProcAttr field 'Unshareflags' in struct literal
  </code></pre>
  
  <p>From the documentation I understand it does not work in a mac. I tried running it on an Ubuntu VM:</p>
  
  <blockquote>
    <p>Linux xxx 4.2.0-27-generic #32~14.04.1-Ubuntu SMP Fri Jan 22 15:32:26
    UTC 2016 x86_64 x86_64 x86_64 GNU/Linux</p>
  </blockquote>
  
  <p>Doesn't work as a sudo user either.</p>