Taking a screenshot using selenium

new_stacktrace.log

Connecting
Traceback (most recent call last):
  File "screenshot.py", line 16, in <module>
    desired_capabilities=desired_capabilities,
  File "/Users/daz/.virtualenvs/1a5c5f7263517393/lib/python2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 63, in __init__
    self.start_session(desired_capabilities, browser_profile)
  File "/Users/daz/.virtualenvs/1a5c5f7263517393/lib/python2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 105, in start_session
    'desiredCapabilities': desired_capabilities,
  File "/Users/daz/.virtualenvs/1a5c5f7263517393/lib/python2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 156, in execute
    self.error_handler.check_response(response)
  File "/Users/daz/.virtualenvs/1a5c5f7263517393/lib/python2.7/site-packages/selenium/webdriver/remote/errorhandler.py", line 125, in check_response
    raise exception_class(value)
selenium.common.exceptions.WebDriverException: Message: 'The requested combination of browser, version and OS is currently unsupported in this version of Selenium (Webdriver): "safari " on "Mac 10.6"' 

screenshot.py

#!/usr/bin/env python
from selenium import webdriver
import sys

url = sys.argv[1] # http://<user>:<apikey>@ondemand.saucelabs.com:80/wd/hub

desired_capabilities={
    'browserName': 'safari',
    'javascriptEnabled': True,
    'platform': 'MAC',
    'max-duration': 90,
}
print 'Connecting'
driver = webdriver.Remote(
    command_executor=url,
    desired_capabilities=desired_capabilities,
)
print 'Navigating'
driver.get('http://www.google.com')
print 'Taking screenshot'
driver.get_screenshot_as_base64()
print 'Quitting'
driver.quit()
print 'Done.'

stacktrace.log

Connecting
Navigating
Taking screenshot
Traceback (most recent call last):
  File "./test.py", line 21, in <module>
    driver.get_screenshot_as_base64()
  File "/Users/daz/.virtualenvs/1368fa811d6ec01d/lib/python2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 720, in get_screenshot_as_base64
    return self.execute(Command.SCREENSHOT)['value']
  File "/Users/daz/.virtualenvs/1368fa811d6ec01d/lib/python2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 156, in execute
    self.error_handler.check_response(response)
  File "/Users/daz/.virtualenvs/1368fa811d6ec01d/lib/python2.7/site-packages/selenium/webdriver/remote/errorhandler.py", line 147, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: u'ERROR Selenium Server in Sauce Labs was already shut down'