function _nvm_list
    set --local versions $nvm_data/*
    set --query versions[1] \
        && string match --entire --regex (string match --regex "v\d.+" $versions \
            | string escape --style=regex \
            | string join "|"
        ) <$nvm_data/.index

    command --all node | string match --quiet --invert --regex "^$nvm_data" \
        && echo system
end