InvalidArgumentException: Message: invalid argument: user data directory is already in use error using --user-data-dir to start Chrome using Selenium
Solution 1:
This error message...
selenium.common.exceptions.InvalidArgumentException: Message: invalid argument: user data directory is already in use, please specify a unique value for --user-data-dir argument, or don't use --user-data-dir
...implies that the ChromeDriver was unable to initiate the new Chrome Browser session using the specified user data directory
as it was already in use.
This error can be reproduced as follows:
-
Code Block:
from selenium import webdriver import getpass options = webdriver.ChromeOptions() options.add_argument("start-maximized") options.add_argument(r"--user-data-dir=C:\Users\{}\AppData\Local\Google\Chrome\User Data".format(getpass.getuser())) driver = webdriver.Chrome(options=options, executable_path=r'C:\WebDrivers\chromedriver.exe') driver.get("https://www.google.com/")
-
Complete relevant traceback:
[12148:21412:0204/035557.731:ERROR:cache_util_win.cc(21)] Unable to move the cache: Access is denied. (0x5) [12148:21412:0204/035557.731:ERROR:cache_util.cc(141)] Unable to move cache folder C:\Users\Soma Bhattacharjee\AppData\Local\Google\Chrome\User Data\ShaderCache\GPUCache to C:\Users\Soma Bhattacharjee\AppData\Local\Google\Chrome\User Data\ShaderCache\old_GPUCache_000 [12148:21412:0204/035557.731:ERROR:disk_cache.cc(178)] Unable to create cache [12148:21412:0204/035557.731:ERROR:shader_disk_cache.cc(605)] Shader Cache Creation failed: -2 Opening in existing browser session. Traceback (most recent call last): File "C:\Users\Soma Bhattacharjee\Desktop\Debanjan\PyPrograms\yandex_ru.py", line 18, in <module> driver = webdriver.Chrome(options=options, executable_path=r'C:\WebDrivers\chromedriver.exe') File "C:\Python\lib\site-packages\selenium\webdriver\chrome\webdriver.py", line 81, in __init__ desired_capabilities=desired_capabilities) File "C:\Python\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 157, in __init__ self.start_session(capabilities, browser_profile) File "C:\Python\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 252, in start_session response = self.execute(Command.NEW_SESSION, parameters) File "C:\Python\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 321, in execute self.error_handler.check_response(response) File "C:\Python\lib\site-packages\selenium\webdriver\remote\errorhandler.py", line 242, in check_response raise exception_class(message, screen, stacktrace) selenium.common.exceptions.InvalidArgumentException: Message: invalid argument: user data directory is already in use, please specify a unique value for --user-data-dir argument, or don't use --user-data-dir
Analysis
The error stack trace clearly complains of Access is denied as the program was unable to move the cache folder ..\ShaderCache\GPUCache
to ..\ShaderCache\old_GPUCache_000
. hence the creation of cache failed and subsequently creation of Shader Cache Creation failed. Though these issues raises the InvalidArgumentException
but forcefully able to open a new window within the existing Chrome Browser Session.
Though the error is thrown, still the new Chrome window gets initiated but remains attached with the already opened Chrome session but the new window can't be controlled by the WebDriver instance. Hence you see data:,
in the url bar.
Solution
You need to take care of a couple of things:
- If you are using the Default Chrome Profile to access webpages for your other work on the same Test Machine, you shouldn't set
user-data-dir
as the User Data as it remains locked by the other Chrome process you have initiated manually.- In the above scenario you need to create and use another Chrome Profile and you can find a detailed discussion in How to open a Chrome Profile through Python
- If you are executing your tests in a isolated test system, you can set
user-data-dir
as ..\User Data\Default to access the Default Chrome Profile.- In the above scenario you need to create and use another Chrome Profile and you can find a detailed discussion in How to use Chrome Profile in Selenium Webdriver Python 3
- However as per best practices you must always create a new Chrome Profile to execute your tests as the Default Chrome Profile may contain Extensions, Bookmarks, Browsing History, etc, and may not load properly.
- You can find a detailed discussion in How to open a Chrome Profile through --user-data-dir argument of Selenium
Solution 2:
The simplest and easiest fix is; to clear existing opened chrome driver: Here're the steps: type task manager to the Spotlight Search/in the Search Window at the task bar or using other ways accessing to task manager. When the Task Manager Wizard/window pops up, search chromedriver, right click on it and then click "End Task". That's it. It's not an eternal fix. Once you opened chrome browser multiple times, you got to do the same step avoid the issue. Hope this helps as am looking for a stable fix.