fixup! Dynamically def method depending on features

lib/rspec/core/formatters/exception_presenter.rb

@@ -41,32 +41,38 @@ def formatted_backtrace(exception=@exception)
             formatted_cause(exception)
         end
 
-        def formatted_cause(exception)
-          return [] unless RSpec::Support::RubyFeatures.supports_exception_cause?
-
-          last_cause = final_exception(exception, [exception])
-          cause = []
-
-          if exception.cause
-            cause << '------------------'
-            cause << '--- Caused by: ---'
-            cause << "#{exception_class_name(last_cause)}:" unless exception_class_name(last_cause) =~ /RSpec/
-
-            encoded_string(exception_message_string(last_cause)).split("\n").each do |line|
-              cause << "  #{line}"
-            end
+        if RSpec::Support::RubyFeatures.supports_exception_cause?
+          def formatted_cause(exception)
+            last_cause = final_exception(exception, [exception])
+            cause = []
+
+            if exception.cause
+              cause << '------------------'
+              cause << '--- Caused by: ---'
+              cause << "#{exception_class_name(last_cause)}:" unless exception_class_name(last_cause) =~ /RSpec/
+
+              encoded_string(exception_message_string(last_cause)).split("\n").each do |line|
+                cause << "  #{line}"
+              end
 
-            unless last_cause.backtrace.nil? || last_cause.backtrace.empty?
-              lines = backtrace_formatter.format_backtrace(last_cause.backtrace, example.metadata)
-              lines = [lines[0]] unless RSpec.configuration.full_cause_backtrace
+              unless last_cause.backtrace.nil? || last_cause.backtrace.empty?
+                lines = backtrace_formatter.format_backtrace(last_cause.backtrace, example.metadata)
+                lines = [lines[0]] unless RSpec.configuration.full_cause_backtrace
 
-              lines.each do |line|
-                cause << ("  #{line}")
+                lines.each do |line|
+                  cause << ("  #{line}")
+                end
               end
             end
-          end
 
-          cause
+            cause
+          end
+        else
+          # :nocov:
+          def formatted_cause(_)
+            []
+          end
+          # :nocov:
         end
 
         def colorized_formatted_backtrace(colorizer=::RSpec::Core::Formatters::ConsoleCodes)