How to correctly use `dap-lldb` for `nixvim`?

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I just saw that there is now a plugin for nixvim dap called dap-lldb, which should make it easier to setup debug configurations for C/C++/Rust.

My setup so far looked something like this:

{ config
, lib
, pkgs
, ...
}:
let
  codelldb-config = {
    name = "Launch (CodeLLDB)";
    type = "codelldb";
    request = "launch";
    program.__raw = ''
      function()
          return vim.fn.input("Path to executable: ", vim.fn.getcwd() .. '/', "file")
      end
    '';
    cwd = ''''${workspaceFolder}'';
    stopOnEntry = false;
  };

  lldb-config = {
    name = "Launch (LLDB)";
    type = "lldb";
    request = "launch";
    program.__raw = ''
      function()
          return vim.fn.input("Path to executable: ", vim.fn.getcwd() .. '/', "file")
      end'';
    cwd = ''''${workspaceFolder}'';
    stopOnEntry = false;
  };
in
{
  extraPackages = with pkgs;
    [
      coreutils
      lldb_18
    ];

  plugins = {
    dap = {
      enable = true;

      adapters = {
        executables = {
          lldb = {
            command = lib.getExe' pkgs.lldb "lldb-vscode";
          };
        };

        servers = {
          codelldb = {
            port = 13000;
            executable = {
              command = "${pkgs.vscode-extensions.vadimcn.vscode-lldb}/share/vscode/extensions/vadimcn.vscode-lldb/adapter/codelldb";
              args = [
                "--port"
                "13000"
              ];
            };
          };
        };
      };

      configurations = {
        c = [ lldb-config ];

        cpp =
          [ lldb-config ]
          ++ lib.optionals pkgs.stdenv.isLinux [
            codelldb-config
          ];

        rust =
          [ lldb-config ]
          ++ lib.optionals pkgs.stdenv.isLinux [
            codelldb-config
          ];
      };

      extensions = {
        dap-ui = {
          enable = true;
        };

        dap-virtual-text = {
          enable = false;
        };
      };
  };
}

This worked okey-ish, but was a bit cumbersome. So the idea was to switch now to this plugging which hopefully should make this easier. The documentation can be found here and I guess the interesting part is also this subpage.

To be honest, Im not entirely sure how to use this plugin correctly… I tried the following:

{ config
, lib
, pkgs
, ...
}:
{
  extraPackages = with pkgs;
    [
      coreutils
      lldb_18
    ];

  plugins = {
    dap = {
      enable = true;

      adapters = {
        executables = {
          lldb = {
            command = lib.getExe' pkgs.lldb "lldb-vscode";
          };
        };

        servers = {
          codelldb = {
            port = 13000;
            executable = {
              command = "${pkgs.vscode-extensions.vadimcn.vscode-lldb}/share/vscode/extensions/vadimcn.vscode-lldb/adapter/codelldb";
              args = [
                "--port"
                "13000"
              ];
            };
          };
        };
      };

      configurations = {
      };

      extensions = {
        dap-ui = {
          enable = true;
        };

        dap-virtual-text = {
          enable = false;
        };
      };
    };
    dap-lldb = {
      enable = true;
      settings.configurations = {
        rust = [
          {
            cwd = "$\${workspaceFolder}";
            name = "Debug";
            program = {
              __raw = ''
                function(selection)
                   local targets = list_targets(selection)
              
                   if targets == nil then
                      return nil
                   end
              
                   if #targets == 0 then
                      return read_target()
                   end
              
                   if #targets == 1 then
                      return targets[1]
                   end
              
                   local options = { "Select a target:" }
              
                   for index, target in ipairs(targets) do
                      local parts = vim.split(target, sep, { trimempty = true })
                      local option = string.format("%d. %s", index, parts[#parts])
                      table.insert(options, option)
                   end
              
                   local choice = vim.fn.inputlist(options)
              
                   return targets[choice]
                end
            '';
          };
          request = "launch";
          stopOnEntry = false;
          type = "lldb";
          }
        ]
      }
    };
  };
}

but:

  1. This does not work. Trying to run a Rust application with the debugger results in a complaint that I need to register a dap.configurations.rust entry, and
  2. This does not seem to be much more simple than writing in the original way…

So, in short, how would a correct example config look like for dap-lldb?