title: How to troubleshoot a hanging Paho Python Mqtt Single Publish
body: <p>I'm looking for ways to trouble shoot issues publishing to a local mosquitto installation (on a RPi).</p>
  
  <p>I find commands from mosquitto_sub and _pub work ok, as is mqtt-os-status.</p>
  
  <p>I've installed paho-mqtt with pip and I'm trying the following:</p>
  
  <pre><code>import paho.mqtt.publish as publish
  publish.single("paho/test/single", "boo-localhost", hostname="localhost")
  </code></pre>
  
  <p>The python command prompt doesn't return... it's been a few minutes since I last tried and I'm just leaving it to see if I get an error message.</p>
  
  <p>Does anyone have any suggestions for where to start troubleshooting? or has anyone come across anything similar? </p>
  
  <p>Matt</p>