title: Selenium with Firefox Nightly Build
body: <p>First, some context. I'm trying to run profile guided optimization with LLVM on Firefox, which means that I have to build the source with clang myself. I've thus downloaded Firefox and built it using mach from source.</p>
  
  <p>However, when I try to use Selenium with my nightly build, it doesn't appear to be able to communicate with the browser. For example, the following code loads yahoo.com and then <strong>hangs on driver.get() indefinitely.</strong> I've tried using explicit and implicit waits and time.sleep() to get the code to move past driver.get(), but I can't find anything. This code works perfectly with the official release of Firefox, just not any version that I compile.</p>
  
  <pre><code>from selenium import webdriver
  from selenium.common.exceptions import TimeoutException
  from selenium.webdriver.firefox.firefox_binary import FirefoxBinary
  from selenium.webdriver.support.ui import WebDriverWait # available since 2.4.0
  from selenium.webdriver.support import expected_conditions as EC # available since 2.26.0
  
  # Create a new instance of the Firefox driver
  binary = FirefoxBinary('/home/kevin/firefox/mozilla-central/obj-x86_64-unknown-linux-gnu/dist/bin/firefox')
  driver = webdriver.Firefox(firefox_binary=binary)
  
  sequence = ['http://www.yahoo.com', 'http://www.cnn.com', 'http://www.amazon.com', 'http://www.newegg.com', 'http://www.google.com']
  
  for url in sequence:
      driver.get(url)
  
  driver.quit()
  </code></pre>
  
  <p>To be clear, the driver is able to ask Firefox to load the first page in the sequence. However, it just hangs forever after that.</p>
  
  <p>I've looked at other threads and tried updating Selenium and Firefox, but nothing has worked so far.</p>
  
  <p>Is there any way to force Selenium to move forward? Failing that, are there any other browser automation frameworks that might be more cooperative with a nightly build of Firefox?</p>