[🐛 Bug]: selenium.common.exceptions.WebDriverException: Message: Host header doesn't match server localhost:60955

[DEADF00D]

What happened?

Running the python program give a direct exception:

Traceback (most recent call last):
  File "/home/deadf00d/Documents/RedditBot/bot.py", line 3, in <module>
    driver = webdriver.Firefox()
  File "/usr/lib/python3.9/site-packages/selenium/webdriver/firefox/webdriver.py", line 180, in __init__
    RemoteWebDriver.__init__(
  File "/usr/lib/python3.9/site-packages/selenium/webdriver/remote/webdriver.py", line 266, in __init__
    self.start_session(capabilities, browser_profile)
  File "/usr/lib/python3.9/site-packages/selenium/webdriver/remote/webdriver.py", line 357, in start_session
    response = self.execute(Command.NEW_SESSION, parameters)
  File "/usr/lib/python3.9/site-packages/selenium/webdriver/remote/webdriver.py", line 420, in execute
    self.error_handler.check_response(response)
  File "/usr/lib/python3.9/site-packages/selenium/webdriver/remote/errorhandler.py", line 244, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: Host header doesn't match server localhost:60955

How can we reproduce the issue?

from selenium import webdriver

driver = webdriver.Firefox()
driver.get("https://dev.to")

Relevant log output

NaN

Operating System

Linux deadf00d 5.14.14-arch1-1 #1 SMP PREEMPT Wed, 20 Oct 2021 21:35:18 +0000 x86_64 GNU/Linux

Selenium version

Python - Selenium 4.0.0

What are the browser(s) and version(s) where you see this issue?

Firefox 93.0 (64 bit)

What are the browser driver(s) and version(s) where you see this issue?

geckodriver 0.30.0 (d372710b98a6 2021-09-16 10:29 +0300)

Are you using Selenium Grid?

No (i guess)

[github-actions]

@DEADF00D, thank you for creating this issue. We will troubleshoot it as soon as we can.

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Thank you!

[lodrantl]

Encountered the same problem on Arch. I don't think it is a Selenium problem but more of a geckodriver problem. I looks like it has something to do with localhost resolving to both IPv6 and IPv4 address while geckodriver is only bound to IPv4.

I found two possible fixes:

1. disable IPv6 completely
2. add the standard localhost config to /etc/hosts (no idea why it works)

127.0.0.1        localhost
::1              localhost

[DEADF00D]

It does work indeed !
Thank you very much.

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.