VSCode’s service install script force its tunnel running in unprivileged systemd, which cannot running in lxc.

Manual installation

# install vscode first
$ code --user-data-dir=~/root tunnel service install # ignore its error
# ...
$ mv ~/.vscode/cli/code-tunnel.service /etc/systemd/system

$ systemctl daemon-reload

$ sudo systemctl enable code-tunnel.service --now

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