[Bug] Cannot copy Copilot CLI output to clipboard in VSCode Server (browser-based remote environment)

[wang11wang]

[Bug] Cannot copy Copilot CLI output to clipboard in VSCode Server (browser-based remote environment)

Summary

When using GitHub Copilot CLI inside a VSCode Server environment (web-based, accessed via browser), the "copy to clipboard" functionality silently fails. There is no fallback, no error message, and no way to retrieve the output that was supposed to be copied.

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Environment

Item	Value
OS	Ubuntu 22.04.4 LTS
VSCode Server	Web-based (--host 0.0.0.0 --port 8080, no GUI)
Terminal	tmux inside VSCode Server integrated terminal
$DISPLAY	(empty — no X11 server)
$WAYLAND_DISPLAY	(empty — no Wayland compositor)
xclip	not found
xsel	not found
wl-copy	not found
pbcopy	not found (Linux)
TTY	not a tty
Copilot CLI version	1.0.67

Relevant environment variables confirming VSCode Server context:

VSCODE_IPC_HOOK_CLI=/tmp/vscode-ipc-*.sock
TERM_PROGRAM=tmux
BROWSER=/usr/lib/vscode-server/bin/helpers/browser.sh
ENTRYPOINT=vscode-server --host 0.0.0.0 --port 8080 --without-connection-token

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Steps to Reproduce

1. Connect to a remote machine running VSCode Server via browser (e.g., http://<host>:8080).
2. Open an integrated terminal (which runs inside a tmux/screen session without a display server).
3. Use GitHub Copilot CLI and trigger any action that copies output to clipboard (e.g., accepting a suggested command).
4. Attempt to paste anywhere — clipboard is empty.

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Expected Behavior

One of the following should happen:

make copy avaliable

In the same env, codex does;

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Actual Behavior

The clipboard copy action silently fails. No output is printed, no warning is shown. The user has no way to access the content that was supposed to be copied.

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