The documentation says I should add an SSH server. The linked page there doesn't tell me much about how, though.

I figured I'll copy /run/current-system/configuration.scm somewhere, edit it, and guix system reconfigure /etc/config.scm.

But alas, that ends with:

Git error: unsupported URL protocol

In the traceback above, I see references to /home/ludo/<something>. I suppose it is trying to fetch channels from there or something?