title: source: not found in shell script?
body: <p>I want to activate a virtual env in shell script, so I write a simple script as follow:</p>
  
  <pre><code>#!/bin/bash
  
  source ~/env/lib/bin/activate
  #nohup python mock_run.py
  #echo $! &gt; save_pid.txt
  </code></pre>
  
  <p>I start the script with <code>sh start.sh</code>, but I got error as follow:</p>
  
  <pre><code>start.sh: 3: start.sh: source: not found
  </code></pre>
  
  <p>I run <code>source ~/env/lib/bin/activate</code> is ok, so why can not in shell script?</p>