     alias NervesSystemCompatibility.Database
 
     @chart_dir "tmp/nerves_system_compatibility"
-    @row_opts [column_width: 20]
 
     def build(opts \\ []) do
       chart_dir = opts[:chart_dir] || @chart_dir


    defp build_chart_for_target(target, opts) do
      column_labels = [target, "Erlang/OTP", "Nerves", "Nerves System BR", "Buildroot", "Linux"]

      header = [
        table_row(column_labels, @row_opts),
        divider_row(length(column_labels), @row_opts)
      ]

      data_rows =
        for version <- Database.get({target, :versions}) do

      }
    end

    defp table_row(values) when is_list(values) do
      ["|", Enum.map(values, &pad_table_cell/1) |> Enum.intersperse("|"), "|"]
      |> Enum.join()
    end

    defp divider_row(cell_count) when is_integer(cell_count) do
      ["|", List.duplicate(pad_table_cell("---"), cell_count) |> Enum.intersperse("|"), "|"]
      |> Enum.join()
    end

    defp pad_table_cell(value), do: " #{value} "
  end

  defmodule Database do
