title: Mac OS - Failed to install python-spidermonkey because nspr not found
body: <p>Trying to install python-spidermonkey using pip on my Mac OS, failed to do so because it's missing nspr:</p>
  
  <pre><code>$ pip install python-spidermonkey
  Downloading/unpacking python-spidermonkey
    Running setup.py egg_info for package python-spidermonkey
      Traceback (most recent call last):
        File "&lt;string&gt;", line 16, in &lt;module&gt;
        File "/Users/smin/ENV/build/python-spidermonkey/setup.py", line 186, in &lt;module&gt;
          **platform_config()
        File "/Users/smin/ENV/build/python-spidermonkey/setup.py", line 143, in platform_config
          return nspr_config(config=config)
        File "/Users/smin/ENV/build/python-spidermonkey/setup.py", line 87, in nspr_config
          return pkg_config("nspr", config)
        File "/Users/smin/ENV/build/python-spidermonkey/setup.py", line 59, in pkg_config
          raise RuntimeError("No package configuration found for: %s" % pkg_name)
      RuntimeError: No package configuration found for: nspr
      Complete output from command python setup.py egg_info:
      Traceback (most recent call last):
  
    File "&lt;string&gt;", line 16, in &lt;module&gt;
  
    File "/Users/shengjiemin/work/Ceilo-ENV/build/python-spidermonkey/setup.py", line 186, in &lt;module&gt;
  
      **platform_config()
  
    File "/Users/smin/rmonkey/setup.py", line 143, in platform_config
  
      return nspr_config(config=config)
  
    File "/Users/smin/ENV/build/python-spidermonkey/setup.py", line 87, in nspr_config
  
      return pkg_config("nspr", config)
  
    File "/Users/smin/ENV/build/python-spidermonkey/setup.py", line 59, in pkg_config
  
      raise RuntimeError("No package configuration found for: %s" % pkg_name)
  
  RuntimeError: No package configuration found for: nspr
  
  ----------------------------------------
  Command python setup.py egg_info failed with error code 1 in /Users/smin/ENV/build/python-spidermonkey
  </code></pre>
  
  <p>I then tried to install nspr:</p>
  
  <pre><code>sudo port install nspr
  </code></pre>
  
  <p>but it didn't make any difference, still the same error. Any ideas?</p>