title: Failed to unpack the installation folder
body: <p>I am trying to follow an Adafruit tutorial which requires installing pySerial. I am running mac 10.8 and run into this error when I try to unpack the installation folder. I go to the directory the file is placed and type:</p>
  
  <pre><code>    tar -xzf pyserial-2.6.tar.gz
  </code></pre>
  
  <p>And then the terminal prints:</p>
  
  <pre><code>    tar: Error opening archive: Failed to open 'pyserial-2.6.tar.gz'
  </code></pre>
  
  <p>I can't seem to find what I could be doing wrong, so any advice would be appreciated. </p>
  
  <p>For those looking for the tutorial, the link can be found here: <a href="http://learn.adafruit.com/arduino-lesson-17-email-sending-movement-detector/installing-python-and-pyserial" rel="nofollow">http://learn.adafruit.com/arduino-lesson-17-email-sending-movement-detector/installing-python-and-pyserial</a></p>