"Failed to connect to the browser" with pure CDP mode on Linux ARM64

[nyg]

Hello,

I've seen this: #4026 and trying it on my Raspberry Pi 5 running Debian.

$ uname -a
Linux raspberrypi5 6.12.34+rpt-rpi-2712 #1 SMP PREEMPT Debian 1:6.12.34-1+rpt1~bookworm (2025-06-26) aarch64 GNU/Linux

My code is the following:

from seleniumbase import sb_cdp

url = "https://www.autoscout24.ch/fr/d/mazda-mx-5-18i-16v-20th-anniversary-12851609"
sb = sb_cdp.Chrome(url)
sb.solve_captcha()
sb.assert_element("h1.chakra-text", 15)
sb.save_screenshot("screen.png")
sb.driver.stop()

I've installed chromium using apt install chromium.

$ which chromium
/usr/bin/chromium
$ chromium --version
Chromium 142.0.7444.59 built on Debian GNU/Linux 12 (bookworm)

When I run my SB script I get the following error:

$ python test.py

start error

X11 display failed! Will use regular xvfb!
Traceback (most recent call last):
  File "/home/user/dev/autoscout-visualizer/crawler/venv/lib/python3.14/site-packages/seleniumbase/undetected/cdp_driver/browser.py", line 121, in create
    await instance.start()
  File "/home/user/dev/autoscout-visualizer/crawler/venv/lib/python3.14/site-packages/seleniumbase/undetected/cdp_driver/browser.py", line 503, in start
    raise Exception(
    ...<7 lines>...
    )
Exception:
                    --------------------------------
                    Failed to connect to the browser
                    --------------------------------


During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/user/dev/autoscout-visualizer/crawler/venv/lib/python3.14/site-packages/seleniumbase/undetected/cdp_driver/cdp_util.py", line 630, in start
    driver = await Browser.create(config)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/dev/autoscout-visualizer/crawler/venv/lib/python3.14/site-packages/seleniumbase/undetected/cdp_driver/browser.py", line 125, in create
    await instance.start()
  File "/home/user/dev/autoscout-visualizer/crawler/venv/lib/python3.14/site-packages/seleniumbase/undetected/cdp_driver/browser.py", line 503, in start
    raise Exception(
    ...<7 lines>...
    )
Exception:
                    --------------------------------
                    Failed to connect to the browser
                    --------------------------------


During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/user/dev/autoscout-visualizer/crawler/venv/lib/python3.14/site-packages/seleniumbase/undetected/cdp_driver/browser.py", line 121, in create
    await instance.start()
  File "/home/user/dev/autoscout-visualizer/crawler/venv/lib/python3.14/site-packages/seleniumbase/undetected/cdp_driver/browser.py", line 503, in start
    raise Exception(
    ...<7 lines>...
    )
Exception:
                    --------------------------------
                    Failed to connect to the browser
                    --------------------------------


During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/user/dev/autoscout-visualizer/crawler/test.py", line 5, in <module>
    sb = sb_cdp.Chrome(url, xvfb=True)
  File "/home/user/dev/autoscout-visualizer/crawler/venv/lib/python3.14/site-packages/seleniumbase/core/sb_cdp.py", line 2894, in __init__
    driver = cdp_util.start_sync(**kwargs)
  File "/home/user/dev/autoscout-visualizer/crawler/venv/lib/python3.14/site-packages/seleniumbase/undetected/cdp_driver/cdp_util.py", line 711, in start_sync
    return loop.run_until_complete(start(*args, **kwargs))
           ~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/.local/share/pyenv/versions/3.14.0/lib/python3.14/asyncio/base_events.py", line 719, in run_until_complete
    return future.result()
           ~~~~~~~~~~~~~^^
  File "/home/user/dev/autoscout-visualizer/crawler/venv/lib/python3.14/site-packages/seleniumbase/undetected/cdp_driver/cdp_util.py", line 633, in start
    driver = await Browser.create(config)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/dev/autoscout-visualizer/crawler/venv/lib/python3.14/site-packages/seleniumbase/undetected/cdp_driver/browser.py", line 125, in create
    await instance.start()
  File "/home/user/dev/autoscout-visualizer/crawler/venv/lib/python3.14/site-packages/seleniumbase/undetected/cdp_driver/browser.py", line 503, in start
    raise Exception(
    ...<7 lines>...
    )
Exception:
                    --------------------------------
                    Failed to connect to the browser
                    --------------------------------

What step have I missed? Some help would be greatly appreciated. :)

[nyg]

Ok, looks like I was missing xvfb. I installed it with apt install xvfb. And… it works!