X11 forwarding for GUI in SSH session? #12

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1. jchak7 commented on Sep 19, 2026

   

   jchak7

   on Sep 19, 2026

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   Looked into this since I wanted the same thing for a Playwright suite.

   Short version: X11 forwarding can't work here, and it's not something the action can add. The ssh …@gha.warp.build command connects to a tmate relay, not to an sshd on the runner. tmate carries the terminal only and doesn't implement the SSH X11 channel, so ssh -X has nothing on the far end to attach to.

   What does work — and gets you the "watch the session live" part — is to run the GUI under Xvfb, serve that display with x11vnc (loopback only), put noVNC in front of it on 6080, and then from inside the debugger session expose 6080 with a cloudflared quick tunnel (no account needed) or ssh -R to a box you control. Open …/vnc.html in a browser and you're looking at the runner's screen.

   I've written it up with a working workflow example in #24. Chain verified end to end locally; the only bit I couldn't exercise from my sandbox was the tunnel provisioning itself, which is fine on a runner.

   If the maintainers would rather have this as a vnc: true input that does the setup and prints the URL in the job summary, I'm happy to build that on top.