A selenium webdriver exception

Question

Today, when i use the selenium webdrive, i got an error. my platform is mac osx . this is my exception log.

ruby-1.9.2-p0 > Selenium::WebDriver.for :firefox
         


        

Answer 1

WebDriver uses port 7054 (the "locking port") as a mutex to ensure that we don't launch two Firefox instances at the same time. Each new instance you create will wait for the mutex before starting the browser, then release it as soon as the browser is open.

So this could indeed be a resource issue - a previously created driver is taking more than 45 seconds to launch and is holding on to the lock for that time.

If this seems unlikely in your case it would be interesting to know what process is holding the lock. Try running lsof -i TCP:7054 in the 45 seconds before it times out.

Running ruby with -d (or setting $DEBUG = true) will also provide some useful info for debugging this further.