ruby/rubygems · error · Psych::SyntaxError

exceeded maximum nesting depth (#{MAX_NESTING_DEPTH})

Error message

exceeded maximum nesting depth (#{MAX_NESTING_DEPTH})

What it means

Error "exceeded maximum nesting depth (#{MAX_NESTING_DEPTH})" thrown in ruby/rubygems.

Source

Thrown at lib/rubygems/yaml_serializer.rb:410

      def consume_value_anchor(val)
        return [nil, val] unless val =~ /^&(\S+)\s+/

        anchor = $1
        [anchor, val.sub(/^&#{Regexp.escape(anchor)}\s+/, "")]
      end

      def register_anchor(name, node)
        if name
          @anchors[name] = node
          node.anchor = name if node.respond_to?(:anchor=)
        end
        node
      end

      def raise_max_nesting!
        message = "exceeded maximum nesting depth (#{MAX_NESTING_DEPTH})"
        if defined?(Psych::VERSION)
          raise Psych::SyntaxError.new(nil, 0, 0, 0, message, nil)
        else
          raise Psych::SyntaxError, message
        end
      end

      def skip_blank_and_comments
        while @lines.any?
          line = @lines[0]
          stripped = line.lstrip
          break unless stripped.empty? || stripped.start_with?("#")
          @lines.shift
        end
      end

      def strip_comment(val)
        return val unless val.include?("#")
        return "" if val.lstrip.start_with?("#")

View on GitHub (pinned to 86cbb817a3)

Solutions

1. Reduce nesting in the YAML metadata; the structure exceeds the maximum allowed depth
2. If the gem is third-party, report the malformed metadata to its author

When it happens

Trigger: Thrown at lib/rubygems/yaml_serializer.rb:410 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ruby/rubygems@86cbb817a3 (2026-08-23). Data as JSON: /api/errors/48e0d2ab172afc0b. Report an issue: GitHub.