do not load DI on ruby 2.5

lib/datadog.rb

@@ -7,5 +7,9 @@
 # Load other products (must follow tracing)
 require_relative 'datadog/profiling'
 require_relative 'datadog/appsec'
-require_relative 'datadog/di'
+# Line probes will not work on Ruby < 2.6 because of lack of :script_compiled
+# trace point. Only load DI on supported Ruby versions.
+if RUBY_VERSION >= '2.6'
+  require_relative 'datadog/di'
+end
 require_relative 'datadog/kit'

lib/datadog/di.rb

@@ -86,6 +86,20 @@ def component
   end
 end
 
-# Activate code tracking by default because line trace points will not work
-# without it.
-Datadog::DI.activate_tracking!
+# :script_compiled trace point was added in Ruby 2.6.
+if RUBY_VERSION >= '2.6'
+  begin
+    # Activate code tracking by default because line trace points will not work
+    # without it.
+    Datadog::DI.activate_tracking!
+  rescue => exc
+    if defined?(Datadog.logger)
+      Datadog.logger.warn("Failed to activate code tracking for DI: #{exc.class}: #{exc}"
+    else
+      # We do not have Datadog logger potentially because DI code tracker is
+      # being loaded early in application boot process and the rest of datadog
+      # wasn't loaded yet. Output to standard error.
+      warn("Failed to activate code tracking for DI: #{exc.class}: #{exc}"
+    end
+  end
+end