Steel Browser docker compose fails on second run: Xvfb Fatal server error, Server is already active for display 10

TL;DR

For "(EE) Fatal server error: Server is already active for display 10 - If this server is no longer running, remove /tmp/.X10-lock and start agai": running Steel Browser's docker compose a second time kills the API with: (EE) Fatal server error: Server is already active for display 10 - If this server is no longer running, remove /tmp/.X10-lock and start again.

(EE) Fatal server error: Server is already active for display 10 - If this server is no longer running, remove /tmp/.X10-lock and start again.

Steps

1. Running Steel Browser's docker compose a second time kills the API with: (EE) Fatal server error: Server is already active for display 10 - If this server is no longer running, remove /tmp/.X10-lock and start again. Xvfb cant start because the previous run left a stale lock file in the container, and the entrypoint didnt clean it up. This isnt arm-specific, it happens on x86 too.
2. The Steel Browser entrypoint was fixed to remove stale X lock files on start (PR #56). Pull the latest image and rebuild with docker-compose up --force-recreate --build so the fixed entrypoint takes effect. As a one-off workaround on an already-running container, delete the stale lock: docker exec [api-container] rm -f /tmp/.X10-lock and restart. The maintainer acknowledged the fix on the issue and closed it.

When to use

You are seeing this: This isnt arm-specific, it happens on x86 too. Use this skill when you run into "Steel Browser docker compose fails on second run: Xvfb Fatal server error, Server is already active for display 10".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Question asked in the thread: Running Steel Browser's docker compose a second time kills the API with: (EE) Fatal server error: Server is already active for display 10 - If this server is no longer running, remove /tmp/.X10-lock and start again. Xvfb cant start because the previous run left a stale lock file in the container, and the entrypoint didnt clean it up. This isnt arm-specific, it happens on x86 too.

Verified answer: The Steel Browser entrypoint was fixed to remove stale X lock files on start (PR #56). Pull the latest image and rebuild with docker-compose up --force-recreate --build so the fixed entrypoint takes effect. As a one-off workaround on an already-running container, delete the stale lock: docker exec [api-container] rm -f /tmp/.X10-lock and restart. The maintainer acknowledged the fix on the issue and closed it.

Source: https://github.com/steel-dev/steel-browser/issues/24

Thread: https://vectle.com/threads/thrl287gxblABXGqWUuHI3Ew