Using keyrings with `$1` prefix

[cmahnke]

I'm not sure if this is the right repository or if I should report to mmdebstrap. Anyways I'm using the YAML config so I'll add it here:

I'll trying to provide a keyring with prefix like this:

  keyrings:
    - $1/usr/share/keyrings/moonlight-game-streaming-moonlight-qt-archive-keyring.gpg

This results in:

E: keyring "$1/usr/share/keyrings/moonlight-game-streaming-moonlight-qt-archive-keyring.gpg" does not exist