我的设置：

• MacOS 10.12.3虚拟环境
• 我已经通过pip install selenium（3.3.1）安装了 selenium 元素。
• 我已经通过brew install geckodriver 0.15.0安装了geckodriver

尝试在intelliJ IDE中运行以下code：

from selenium import webdriver
from selenium.webdriver.common.keys import Keys

driver = webdriver.Firefox(executable_path='/usr/local/opt/geckodriver')
driver.get("https://google.com")
elem = driver.find_element_by_name("q")

并且从第4行（driver = webdriver...）抛出异常：

Traceback (most recent call last):
  File "/Users/itayb/test/main.py", line 4, in <module>
    driver = webdriver.Firefox(executable_path='/usr/local/opt/geckodriver')
  File "/Users/itayb/test/venv/lib/python2.7/site-packages/selenium/webdriver/firefox/webdriver.py", line 145, in __init__
    self.service.start()
  File "/Users/itayb/test/venv/lib/python2.7/site-packages/selenium/webdriver/common/service.py", line 86, in start
    os.path.basename(self.path), self.start_error_message)
selenium.common.exceptions.WebDriverException: Message: 'geckodriver' executable may have wrong permissions. 

Process finished with exit code 1

必须说，executable_path是在尝试在SO. bin文件中看到一些答案后添加的（geckodriver是从命令行执行的，没有任何问题）。我该如何修复这个问题？