lib.options.showDefs

The following is the current implementation of this function.

defs:
    concatMapStrings (
      def:
      let
        # Pretty print the value for display, if successful
        prettyEval = builtins.tryEval (
          lib.generators.toPretty { } (
            lib.generators.withRecursion {
              depthLimit = 10;
              throwOnDepthLimit = false;
            } def.value
          )
        );
        # Split it into its lines
        lines = filter (v: !isList v) (builtins.split "\n" prettyEval.value);
        # Only display the first 5 lines, and indent them for better visibility
        value = concatStringsSep "\n    " (take 5 lines ++ optional (length lines > 5) "...");
        result =
          # Don't print any value if evaluating the value strictly fails
          if !prettyEval.success then
            ""
          # Put it on a new line if it consists of multiple
          else if length lines > 1 then
            ":\n    " + value
          else
            ": " + value;
      in
      "\n- In `${def.file}'${result}"
    ) defs