title: get error: Segmentation fault(core dumped) when run docker-machine
body: <p>I download the latest build of docker-machine from github to /usr/local/bin/docker-machine on my Centos 7, and chmod x for it.</p>
  
  <p>When I run it as <code>docker-machine -v</code>, the error as below:</p>
  
  <blockquote>
    <p>Segmentation fault(core dumped).</p>
  </blockquote>
  
  <p>I run strace docker-machine: </p>
  
  <pre><code>execve("docker-machine", ["docker-machine"], [/* 35 vars */]) = 0
   arch_prctl(ARCH_SET_FS, 0x2690388)      = 0
   --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x7ffba5531788} ---
   +++ killed by SIGSEGV (core dumped) +++
  </code></pre>
  
  <p>who can help me for the error?</p>