From 329b0cd04cee76516c737d50c9f90d329d6d5ce9 Mon Sep 17 00:00:00 2001
From: Munir <munir.abdinur@datadoghq.com>
Date: Mon, 16 Mar 2026 17:08:10 -0400
Subject: [PATCH 01/10] chore(telemetry): track process creation via it headers

---
 gemfiles/ruby_3.4_opentelemetry.gemfile       |  2 +
 gemfiles/ruby_3.4_opentelemetry.gemfile.lock  | 17 +++++++
 lib/datadog/core/environment/identity.rb      | 33 +++++++++++++-
 .../telemetry/transport/http/telemetry.rb     |  5 +++
 lib/datadog/core/utils/spawn_monkey_patch.rb  | 45 +++++++++++++++++++
 5 files changed, 101 insertions(+), 1 deletion(-)
 create mode 100644 lib/datadog/core/utils/spawn_monkey_patch.rb

diff --git a/gemfiles/ruby_3.4_opentelemetry.gemfile b/gemfiles/ruby_3.4_opentelemetry.gemfile
index 7ef9fcc939..9c3a680ec2 100644
--- a/gemfiles/ruby_3.4_opentelemetry.gemfile
+++ b/gemfiles/ruby_3.4_opentelemetry.gemfile
@@ -31,6 +31,8 @@ gem "webrick", ">= 1.8.2"
 gem "opentelemetry-sdk", "~> 1.1"
 gem "opentelemetry-metrics-sdk", ">= 0.8"
 gem "opentelemetry-exporter-otlp-metrics", ">= 0.4"
+gem "opentelemetry-logs-sdk", ">= 0.1"
+gem "opentelemetry-exporter-otlp-logs", ">= 0.1"
 
 group :check do
 
diff --git a/gemfiles/ruby_3.4_opentelemetry.gemfile.lock b/gemfiles/ruby_3.4_opentelemetry.gemfile.lock
index f06bf3b1d1..9a87f43fca 100644
--- a/gemfiles/ruby_3.4_opentelemetry.gemfile.lock
+++ b/gemfiles/ruby_3.4_opentelemetry.gemfile.lock
@@ -62,6 +62,15 @@ GEM
     opentelemetry-api (1.7.0)
     opentelemetry-common (0.23.0)
       opentelemetry-api (~> 1.0)
+    opentelemetry-exporter-otlp-logs (0.3.0)
+      google-protobuf (>= 3.18)
+      googleapis-common-protos-types (~> 1.3)
+      opentelemetry-api (~> 1.1)
+      opentelemetry-common (~> 0.20)
+      opentelemetry-logs-api (~> 0.1)
+      opentelemetry-logs-sdk (~> 0.1)
+      opentelemetry-sdk
+      opentelemetry-semantic_conventions
     opentelemetry-exporter-otlp-metrics (0.6.1)
       google-protobuf (>= 3.18, < 5.0)
       googleapis-common-protos-types (~> 1.3)
@@ -71,6 +80,12 @@ GEM
       opentelemetry-metrics-sdk (~> 0.5)
       opentelemetry-sdk (~> 1.2)
       opentelemetry-semantic_conventions
+    opentelemetry-logs-api (0.2.0)
+      opentelemetry-api (~> 1.0)
+    opentelemetry-logs-sdk (0.4.0)
+      opentelemetry-api (~> 1.2)
+      opentelemetry-logs-api (~> 0.1)
+      opentelemetry-sdk (~> 1.3)
     opentelemetry-metrics-api (0.4.0)
       opentelemetry-api (~> 1.0)
     opentelemetry-metrics-sdk (0.11.1)
@@ -161,7 +176,9 @@ DEPENDENCIES
   json-schema (< 3)
   memory_profiler (~> 0.9)
   mutex_m
+  opentelemetry-exporter-otlp-logs (>= 0.1)
   opentelemetry-exporter-otlp-metrics (>= 0.4)
+  opentelemetry-logs-sdk (>= 0.1)
   opentelemetry-metrics-sdk (>= 0.8)
   opentelemetry-sdk (~> 1.1)
   os (~> 1.1)
diff --git a/lib/datadog/core/environment/identity.rb b/lib/datadog/core/environment/identity.rb
index b39bd39a7c..3b15cc3ebd 100644
--- a/lib/datadog/core/environment/identity.rb
+++ b/lib/datadog/core/environment/identity.rb
@@ -13,18 +13,49 @@ module Environment
       module Identity
         extend Core::Utils::Forking
 
+        ENV_ROOT_SESSION_ID = '_DD_ROOT_RB_SESSION_ID'
+        ENV_PARENT_SESSION_ID = '_DD_PARENT_RB_SESSION_ID'
+
         module_function
 
+        # Seed from env when this process was spawned (Process.spawn, exec).
+        # For fork-based processes these are set by after_fork!.
+        @ancestor_runtime_id = ENV[ENV_ROOT_SESSION_ID]&.freeze
+        @parent_runtime_id = ENV[ENV_PARENT_SESSION_ID]&.freeze
+
         # Retrieves number of classes from runtime
         def id
           @id ||= ::SecureRandom.uuid.freeze
 
           # Check if runtime has changed, e.g. forked.
-          after_fork! { @id = ::SecureRandom.uuid.freeze }
+          after_fork! do
+            @parent_runtime_id = @id
+            @ancestor_runtime_id ||= @id
+            @id = ::SecureRandom.uuid.freeze
+          end
 
           @id
         end
 
+        # Root of the fork tree (Stable Service Instance Identifier). Nil in root process.
+        def ancestor_runtime_id
+          @ancestor_runtime_id
+        end
+
+        # Direct parent's runtime_id. Nil in root process.
+        def parent_runtime_id
+          @parent_runtime_id
+        end
+
+        # Returns session lineage env vars to inject into child process environments.
+        # Allows exec-based child processes (Process.spawn) to reconstruct process lineage.
+        def runtime_propagation_envs
+          ancestor = ancestor_runtime_id
+          current = id
+          root = ancestor || current
+          { ENV_ROOT_SESSION_ID => root, ENV_PARENT_SESSION_ID => current }.freeze
+        end
+
         def pid
           ::Process.pid
         end
diff --git a/lib/datadog/core/telemetry/transport/http/telemetry.rb b/lib/datadog/core/telemetry/transport/http/telemetry.rb
index e2b896afc8..c77b71fa63 100644
--- a/lib/datadog/core/telemetry/transport/http/telemetry.rb
+++ b/lib/datadog/core/telemetry/transport/http/telemetry.rb
@@ -44,11 +44,16 @@ def headers(request_type:, api_key:)
                     'DD-Telemetry-Request-Type' => request_type,
                     'DD-Client-Library-Language' => Core::Environment::Ext::LANG,
                     'DD-Client-Library-Version' => Core::Environment::Identity.gem_datadog_version_semver2,
+                    'DD-Session-ID' => Core::Environment::Identity.id,
 
                     # Enable debug mode for telemetry
                     # 'DD-Telemetry-Debug-Enabled' => 'true',
                   }.tap do |result|
                     result['DD-API-KEY'] = api_key unless api_key.nil?
+                    ancestor = Core::Environment::Identity.ancestor_runtime_id
+                    result['DD-Root-Session-ID'] = ancestor if ancestor
+                    parent = Core::Environment::Identity.parent_runtime_id
+                    result['DD-Parent-Session-ID'] = parent if parent
                   end
                 end
               end
diff --git a/lib/datadog/core/utils/spawn_monkey_patch.rb b/lib/datadog/core/utils/spawn_monkey_patch.rb
new file mode 100644
index 0000000000..ac32578c83
--- /dev/null
+++ b/lib/datadog/core/utils/spawn_monkey_patch.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+require_relative '../environment/identity'
+
+module Datadog
+  module Core
+    module Utils
+      # Monkey patches Process.spawn to inject session lineage env vars
+      # (_DD_ROOT_RB_SESSION_ID, _DD_PARENT_RB_SESSION_ID) into the child's
+      # environment so exec-based child processes can reconstruct process lineage.
+      module SpawnMonkeyPatch
+        def self.apply!
+          return false unless ::Process.respond_to?(:spawn)
+
+          ::Process.singleton_class.prepend(ProcessSpawnPatch)
+
+          true
+        end
+
+        module ProcessSpawnPatch
+          def spawn(*args, **opts)
+            args = SpawnMonkeyPatch.inject_lineage_envs(args)
+            super(*args, **opts)
+          end
+        end
+
+        class << self
+          def inject_lineage_envs(args)
+            lineage = Core::Environment::Identity.runtime_propagation_envs
+
+            if args.first.is_a?(Hash)
+              # env hash provided: merge lineage into it
+              env = args.first.merge(lineage)
+              [env, *args.drop(1)]
+            else
+              # no env hash: prepend ENV merged with lineage
+              env = ENV.to_h.merge(lineage)
+              [env, *args]
+            end
+          end
+        end
+      end
+    end
+  end
+end

From 1ac18f3691c4b50df44acd7d7d9737381a314652 Mon Sep 17 00:00:00 2001
From: "dd-apm-ecosystems-autobot[bot]"
 <214617597+dd-apm-ecosystems-autobot[bot]@users.noreply.github.com>
Date: Mon, 16 Mar 2026 21:18:39 +0000
Subject: [PATCH 02/10] =?UTF-8?q?[=F0=9F=A4=96]=20Lock=20Dependency:=20htt?=
 =?UTF-8?q?ps://github.com/DataDog/dd-trace-rb/actions/runs/23166118107?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 gemfiles/ruby_3.4_opentelemetry.gemfile      |  2 --
 gemfiles/ruby_3.4_opentelemetry.gemfile.lock | 17 -----------------
 2 files changed, 19 deletions(-)

diff --git a/gemfiles/ruby_3.4_opentelemetry.gemfile b/gemfiles/ruby_3.4_opentelemetry.gemfile
index 9c3a680ec2..7ef9fcc939 100644
--- a/gemfiles/ruby_3.4_opentelemetry.gemfile
+++ b/gemfiles/ruby_3.4_opentelemetry.gemfile
@@ -31,8 +31,6 @@ gem "webrick", ">= 1.8.2"
 gem "opentelemetry-sdk", "~> 1.1"
 gem "opentelemetry-metrics-sdk", ">= 0.8"
 gem "opentelemetry-exporter-otlp-metrics", ">= 0.4"
-gem "opentelemetry-logs-sdk", ">= 0.1"
-gem "opentelemetry-exporter-otlp-logs", ">= 0.1"
 
 group :check do
 
diff --git a/gemfiles/ruby_3.4_opentelemetry.gemfile.lock b/gemfiles/ruby_3.4_opentelemetry.gemfile.lock
index 7175b1c7d3..5321186532 100644
--- a/gemfiles/ruby_3.4_opentelemetry.gemfile.lock
+++ b/gemfiles/ruby_3.4_opentelemetry.gemfile.lock
@@ -62,15 +62,6 @@ GEM
     opentelemetry-api (1.7.0)
     opentelemetry-common (0.23.0)
       opentelemetry-api (~> 1.0)
-    opentelemetry-exporter-otlp-logs (0.3.0)
-      google-protobuf (>= 3.18)
-      googleapis-common-protos-types (~> 1.3)
-      opentelemetry-api (~> 1.1)
-      opentelemetry-common (~> 0.20)
-      opentelemetry-logs-api (~> 0.1)
-      opentelemetry-logs-sdk (~> 0.1)
-      opentelemetry-sdk
-      opentelemetry-semantic_conventions
     opentelemetry-exporter-otlp-metrics (0.6.1)
       google-protobuf (>= 3.18, < 5.0)
       googleapis-common-protos-types (~> 1.3)
@@ -80,12 +71,6 @@ GEM
       opentelemetry-metrics-sdk (~> 0.5)
       opentelemetry-sdk (~> 1.2)
       opentelemetry-semantic_conventions
-    opentelemetry-logs-api (0.2.0)
-      opentelemetry-api (~> 1.0)
-    opentelemetry-logs-sdk (0.4.0)
-      opentelemetry-api (~> 1.2)
-      opentelemetry-logs-api (~> 0.1)
-      opentelemetry-sdk (~> 1.3)
     opentelemetry-metrics-api (0.4.0)
       opentelemetry-api (~> 1.0)
     opentelemetry-metrics-sdk (0.11.1)
@@ -176,9 +161,7 @@ DEPENDENCIES
   json-schema (< 3)
   memory_profiler (~> 0.9)
   mutex_m
-  opentelemetry-exporter-otlp-logs (>= 0.1)
   opentelemetry-exporter-otlp-metrics (>= 0.4)
-  opentelemetry-logs-sdk (>= 0.1)
   opentelemetry-metrics-sdk (>= 0.8)
   opentelemetry-sdk (~> 1.1)
   os (~> 1.1)

From 309042dae4ea3b9ea2428781de3b46c56425520d Mon Sep 17 00:00:00 2001
From: Munir <munir.abdinur@datadoghq.com>
Date: Mon, 23 Mar 2026 15:47:35 -0400
Subject: [PATCH 03/10] add spawnmonkeypatch to only once

---
 lib/datadog/core/configuration/components.rb | 6 ++++--
 spec/support/core_helpers.rb                 | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/datadog/core/configuration/components.rb b/lib/datadog/core/configuration/components.rb
index 98ff497661..099ca015e6 100644
--- a/lib/datadog/core/configuration/components.rb
+++ b/lib/datadog/core/configuration/components.rb
@@ -12,6 +12,7 @@
 require_relative '../workers/runtime_metrics'
 require_relative '../remote/component'
 require_relative '../utils/at_fork_monkey_patch'
+require_relative '../utils/spawn_monkey_patch'
 require_relative '../utils/only_once'
 require_relative '../../tracing/component'
 require_relative '../../profiling/component'
@@ -31,7 +32,7 @@ module Configuration
       # Global components for the trace library.
       class Components
         # Class-level constant to ensure fork patch is applied only once
-        AT_FORK_ONLY_ONCE = Utils::OnlyOnce.new
+        PATCH_ONLY_ONCE = Utils::OnlyOnce.new
 
         class << self
           def build_health_metrics(settings, logger, telemetry)
@@ -128,8 +129,9 @@ def initialize(settings)
           Deprecations.log_deprecations_from_all_sources(@logger)
 
           # Register fork handling once globally
-          self.class::AT_FORK_ONLY_ONCE.run do
+          self.class::PATCH_ONLY_ONCE.run do
             Utils::AtForkMonkeyPatch.apply!
+            Utils::SpawnMonkeyPatch.apply!
 
             # Register callback that calls Components.after_fork
             Utils::AtForkMonkeyPatch.at_fork(:child) do
diff --git a/spec/support/core_helpers.rb b/spec/support/core_helpers.rb
index b24345c9ee..f383f15a17 100644
--- a/spec/support/core_helpers.rb
+++ b/spec/support/core_helpers.rb
@@ -145,7 +145,7 @@ def reset_at_fork_monkey_patch_for_components!
         # because normally it would be added during library initialization
         # and after the fork monkey patch test runs, the handler would get
         # cleared out.
-        Datadog::Core::Configuration::Components.const_get(:AT_FORK_ONLY_ONCE).send(:reset_ran_once_state_for_tests)
+        Datadog::Core::Configuration::Components.const_get(:PATCH_ONLY_ONCE).send(:reset_ran_once_state_for_tests)
 
         # We also need to clear out the handlers because we could have
         # the handlers registered from the library initialization time,

From 5e656d1b3c0f9a6ab3745a514cfd955e290b47ec Mon Sep 17 00:00:00 2001
From: Munir <munir.abdinur@datadoghq.com>
Date: Mon, 23 Mar 2026 15:53:21 -0400
Subject: [PATCH 04/10] use root instead of ancestor id (term used in
 dd-trace-py)

---
 lib/datadog/core/environment/identity.rb              | 11 +++++------
 .../core/telemetry/transport/http/telemetry.rb        |  4 ++--
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/lib/datadog/core/environment/identity.rb b/lib/datadog/core/environment/identity.rb
index 3b15cc3ebd..2110e67cfd 100644
--- a/lib/datadog/core/environment/identity.rb
+++ b/lib/datadog/core/environment/identity.rb
@@ -20,7 +20,7 @@ module Identity
 
         # Seed from env when this process was spawned (Process.spawn, exec).
         # For fork-based processes these are set by after_fork!.
-        @ancestor_runtime_id = ENV[ENV_ROOT_SESSION_ID]&.freeze
+        @root_runtime_id = ENV[ENV_ROOT_SESSION_ID]&.freeze
         @parent_runtime_id = ENV[ENV_PARENT_SESSION_ID]&.freeze
 
         # Retrieves number of classes from runtime
@@ -30,7 +30,7 @@ def id
           # Check if runtime has changed, e.g. forked.
           after_fork! do
             @parent_runtime_id = @id
-            @ancestor_runtime_id ||= @id
+            @root_runtime_id ||= @id
             @id = ::SecureRandom.uuid.freeze
           end
 
@@ -38,8 +38,8 @@ def id
         end
 
         # Root of the fork tree (Stable Service Instance Identifier). Nil in root process.
-        def ancestor_runtime_id
-          @ancestor_runtime_id
+        def root_runtime_id
+          @root_runtime_id
         end
 
         # Direct parent's runtime_id. Nil in root process.
@@ -50,9 +50,8 @@ def parent_runtime_id
         # Returns session lineage env vars to inject into child process environments.
         # Allows exec-based child processes (Process.spawn) to reconstruct process lineage.
         def runtime_propagation_envs
-          ancestor = ancestor_runtime_id
+          root = root_runtime_id || id
           current = id
-          root = ancestor || current
           { ENV_ROOT_SESSION_ID => root, ENV_PARENT_SESSION_ID => current }.freeze
         end
 
diff --git a/lib/datadog/core/telemetry/transport/http/telemetry.rb b/lib/datadog/core/telemetry/transport/http/telemetry.rb
index c77b71fa63..b37f7b4be4 100644
--- a/lib/datadog/core/telemetry/transport/http/telemetry.rb
+++ b/lib/datadog/core/telemetry/transport/http/telemetry.rb
@@ -50,8 +50,8 @@ def headers(request_type:, api_key:)
                     # 'DD-Telemetry-Debug-Enabled' => 'true',
                   }.tap do |result|
                     result['DD-API-KEY'] = api_key unless api_key.nil?
-                    ancestor = Core::Environment::Identity.ancestor_runtime_id
-                    result['DD-Root-Session-ID'] = ancestor if ancestor
+                    root = Core::Environment::Identity.root_runtime_id
+                    result['DD-Root-Session-ID'] = root if root
                     parent = Core::Environment::Identity.parent_runtime_id
                     result['DD-Parent-Session-ID'] = parent if parent
                   end

From f72882b97a1dbf6534f011d943502505cb50d3af Mon Sep 17 00:00:00 2001
From: Munir <munir.abdinur@datadoghq.com>
Date: Mon, 23 Mar 2026 16:12:09 -0400
Subject: [PATCH 05/10] lint and clean up implementation

---
 .../core/configuration/config_helper.rb       |  6 ++++
 lib/datadog/core/environment/identity.rb      |  6 ++--
 lib/datadog/core/utils/spawn_monkey_patch.rb  | 28 ++++++++-----------
 sig/datadog/core/utils/spawn_monkey_patch.rbs | 16 +++++++++++
 4 files changed, 37 insertions(+), 19 deletions(-)
 create mode 100644 sig/datadog/core/utils/spawn_monkey_patch.rbs

diff --git a/lib/datadog/core/configuration/config_helper.rb b/lib/datadog/core/configuration/config_helper.rb
index f7d6d116f2..fcef1b46cb 100644
--- a/lib/datadog/core/configuration/config_helper.rb
+++ b/lib/datadog/core/configuration/config_helper.rb
@@ -40,6 +40,12 @@ def key?(name)
           !get_environment_variable(name).nil?
         end
 
+        # Returns the source environment as a Hash. Used when the full environment
+        # must be passed through (e.g. Process.spawn child env).
+        def to_h
+          @source_env.to_h
+        end
+
         alias_method :has_key?, :key?
         alias_method :include?, :key?
         alias_method :member?, :key?
diff --git a/lib/datadog/core/environment/identity.rb b/lib/datadog/core/environment/identity.rb
index 2110e67cfd..48619ee257 100644
--- a/lib/datadog/core/environment/identity.rb
+++ b/lib/datadog/core/environment/identity.rb
@@ -20,8 +20,8 @@ module Identity
 
         # Seed from env when this process was spawned (Process.spawn, exec).
         # For fork-based processes these are set by after_fork!.
-        @root_runtime_id = ENV[ENV_ROOT_SESSION_ID]&.freeze
-        @parent_runtime_id = ENV[ENV_PARENT_SESSION_ID]&.freeze
+        @root_runtime_id = DATADOG_ENV[ENV_ROOT_SESSION_ID]&.freeze
+        @parent_runtime_id = DATADOG_ENV[ENV_PARENT_SESSION_ID]&.freeze
 
         # Retrieves number of classes from runtime
         def id
@@ -52,7 +52,7 @@ def parent_runtime_id
         def runtime_propagation_envs
           root = root_runtime_id || id
           current = id
-          { ENV_ROOT_SESSION_ID => root, ENV_PARENT_SESSION_ID => current }.freeze
+          {ENV_ROOT_SESSION_ID => root, ENV_PARENT_SESSION_ID => current}.freeze
         end
 
         def pid
diff --git a/lib/datadog/core/utils/spawn_monkey_patch.rb b/lib/datadog/core/utils/spawn_monkey_patch.rb
index ac32578c83..c2061136dd 100644
--- a/lib/datadog/core/utils/spawn_monkey_patch.rb
+++ b/lib/datadog/core/utils/spawn_monkey_patch.rb
@@ -5,9 +5,6 @@
 module Datadog
   module Core
     module Utils
-      # Monkey patches Process.spawn to inject session lineage env vars
-      # (_DD_ROOT_RB_SESSION_ID, _DD_PARENT_RB_SESSION_ID) into the child's
-      # environment so exec-based child processes can reconstruct process lineage.
       module SpawnMonkeyPatch
         def self.apply!
           return false unless ::Process.respond_to?(:spawn)
@@ -19,24 +16,23 @@ def self.apply!
 
         module ProcessSpawnPatch
           def spawn(*args, **opts)
-            args = SpawnMonkeyPatch.inject_lineage_envs(args)
-            super(*args, **opts)
+            args.replace(SpawnMonkeyPatch.inject_lineage_envs(args))
+            super
           end
         end
 
         class << self
+          # Process.spawn(env?, cmd, ...): env is optional first arg (Hash). When present, merge
+          # runtime_ids into it; when absent, prepend full ENV + runtime_ids so the child inherits both.
           def inject_lineage_envs(args)
-            lineage = Core::Environment::Identity.runtime_propagation_envs
-
-            if args.first.is_a?(Hash)
-              # env hash provided: merge lineage into it
-              env = args.first.merge(lineage)
-              [env, *args.drop(1)]
-            else
-              # no env hash: prepend ENV merged with lineage
-              env = ENV.to_h.merge(lineage)
-              [env, *args]
-            end
+            runtime_ids = Core::Environment::Identity.runtime_propagation_envs
+            env_provided = Hash === args.first
+
+            base_env = env_provided ? args.first : DATADOG_ENV.to_h
+            env = base_env.merge(runtime_ids)
+            rest = env_provided ? args.drop(1) : args
+
+            [env, *rest]
           end
         end
       end
diff --git a/sig/datadog/core/utils/spawn_monkey_patch.rbs b/sig/datadog/core/utils/spawn_monkey_patch.rbs
new file mode 100644
index 0000000000..e640e63869
--- /dev/null
+++ b/sig/datadog/core/utils/spawn_monkey_patch.rbs
@@ -0,0 +1,16 @@
+module Datadog
+    module Core
+      module Utils
+        module SpawnMonkeyPatch
+          def self.apply!: () -> (false | true)
+  
+          module ProcessSpawnPatch
+            def spawn: (*untyped args, **untyped opts) -> untyped
+          end
+  
+          def self.inject_lineage_envs: (untyped args) -> untyped
+        end
+      end
+    end
+  end
+end
\ No newline at end of file

From 4fbe9f89ee9c6ffdc6ed7494be31709a5224b4e6 Mon Sep 17 00:00:00 2001
From: Munir <munir.abdinur@datadoghq.com>
Date: Mon, 23 Mar 2026 16:26:45 -0400
Subject: [PATCH 06/10] add tests and fix circular import with Datadogenv usage

---
 lib/datadog/core.rb                           |  9 +++-
 lib/datadog/core/environment/identity.rb      | 13 +----
 lib/datadog/core/utils/spawn_monkey_patch.rb  |  3 --
 lib/datadog/tracing/tracer.rb                 |  1 +
 .../core/configuration/components_spec.rb     | 22 +++++++++
 .../core/configuration/config_helper_spec.rb  | 13 +++++
 .../datadog/core/environment/identity_spec.rb | 42 ++++++++++++++++
 .../core/utils/spawn_monkey_patch_spec.rb     | 48 +++++++++++++++++++
 8 files changed, 136 insertions(+), 15 deletions(-)
 create mode 100644 spec/datadog/core/utils/spawn_monkey_patch_spec.rb

diff --git a/lib/datadog/core.rb b/lib/datadog/core.rb
index d178cbd2f8..e438bfe68f 100644
--- a/lib/datadog/core.rb
+++ b/lib/datadog/core.rb
@@ -2,6 +2,14 @@
 
 require_relative 'core/deprecations'
 require_relative 'core/configuration/config_helper'
+
+# DATADOG_ENV must be defined before requiring extensions, because extensions loads
+# components (via configuration), which loads spawn_monkey_patch, which loads identity;
+# identity uses DATADOG_ENV at load time.
+module Datadog
+  DATADOG_ENV = Core::Configuration::ConfigHelper.new
+end
+
 require_relative 'core/extensions'
 
 # We must load core extensions to make certain global APIs
@@ -22,7 +30,6 @@ module Core
       end
   end
 
-  DATADOG_ENV = Core::Configuration::ConfigHelper.new
   extend Core::Extensions
 
   # Add shutdown hook:
diff --git a/lib/datadog/core/environment/identity.rb b/lib/datadog/core/environment/identity.rb
index 48619ee257..1230f02620 100644
--- a/lib/datadog/core/environment/identity.rb
+++ b/lib/datadog/core/environment/identity.rb
@@ -18,17 +18,14 @@ module Identity
 
         module_function
 
-        # Seed from env when this process was spawned (Process.spawn, exec).
-        # For fork-based processes these are set by after_fork!.
         @root_runtime_id = DATADOG_ENV[ENV_ROOT_SESSION_ID]&.freeze
         @parent_runtime_id = DATADOG_ENV[ENV_PARENT_SESSION_ID]&.freeze
 
-        # Retrieves number of classes from runtime
         def id
           @id ||= ::SecureRandom.uuid.freeze
 
-          # Check if runtime has changed, e.g. forked.
           after_fork! do
+            # Order matters: capture @id before overwriting
             @parent_runtime_id = @id
             @root_runtime_id ||= @id
             @id = ::SecureRandom.uuid.freeze
@@ -37,22 +34,16 @@ def id
           @id
         end
 
-        # Root of the fork tree (Stable Service Instance Identifier). Nil in root process.
         def root_runtime_id
           @root_runtime_id
         end
 
-        # Direct parent's runtime_id. Nil in root process.
         def parent_runtime_id
           @parent_runtime_id
         end
 
-        # Returns session lineage env vars to inject into child process environments.
-        # Allows exec-based child processes (Process.spawn) to reconstruct process lineage.
         def runtime_propagation_envs
-          root = root_runtime_id || id
-          current = id
-          {ENV_ROOT_SESSION_ID => root, ENV_PARENT_SESSION_ID => current}.freeze
+          {ENV_ROOT_SESSION_ID => root_runtime_id || id, ENV_PARENT_SESSION_ID => id}.freeze
         end
 
         def pid
diff --git a/lib/datadog/core/utils/spawn_monkey_patch.rb b/lib/datadog/core/utils/spawn_monkey_patch.rb
index c2061136dd..9bbf1d5f33 100644
--- a/lib/datadog/core/utils/spawn_monkey_patch.rb
+++ b/lib/datadog/core/utils/spawn_monkey_patch.rb
@@ -7,10 +7,7 @@ module Core
     module Utils
       module SpawnMonkeyPatch
         def self.apply!
-          return false unless ::Process.respond_to?(:spawn)
-
           ::Process.singleton_class.prepend(ProcessSpawnPatch)
-
           true
         end
 
diff --git a/lib/datadog/tracing/tracer.rb b/lib/datadog/tracing/tracer.rb
index 637f30575f..dd9ab6404a 100644
--- a/lib/datadog/tracing/tracer.rb
+++ b/lib/datadog/tracing/tracer.rb
@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 
+require_relative '../core'
 require_relative '../core/environment/ext'
 require_relative '../core/environment/socket'
 
diff --git a/spec/datadog/core/configuration/components_spec.rb b/spec/datadog/core/configuration/components_spec.rb
index 2171b28f8a..613bfe6016 100644
--- a/spec/datadog/core/configuration/components_spec.rb
+++ b/spec/datadog/core/configuration/components_spec.rb
@@ -736,4 +736,26 @@
       end
     end
   end
+
+  describe 'PATCH_ONLY_ONCE monkey patches' do
+    reset_at_fork_monkey_patch_for_components!
+
+    before do
+      skip 'Fork not supported' unless Process.respond_to?(:fork)
+      skip 'Process.spawn not supported' unless Process.respond_to?(:spawn)
+    end
+
+    it 'applies AtForkMonkeyPatch and SpawnMonkeyPatch when Components is initialized' do
+      expect_in_fork do
+        described_class.new(Datadog::Core::Configuration::Settings.new)
+
+        expect(Process.singleton_class.ancestors).to include(
+          Datadog::Core::Utils::AtForkMonkeyPatch::ProcessMonkeyPatch,
+        )
+        expect(Process.singleton_class.ancestors).to include(
+          Datadog::Core::Utils::SpawnMonkeyPatch::ProcessSpawnPatch,
+        )
+      end
+    end
+  end
 end
diff --git a/spec/datadog/core/configuration/config_helper_spec.rb b/spec/datadog/core/configuration/config_helper_spec.rb
index 25d5f51453..5218133b73 100644
--- a/spec/datadog/core/configuration/config_helper_spec.rb
+++ b/spec/datadog/core/configuration/config_helper_spec.rb
@@ -68,6 +68,19 @@
     end
   end
 
+  describe '#to_h' do
+    subject do
+      described_class.new(
+        source_env: {'DD_SERVICE' => 'my-app', 'PATH' => '/usr/bin'},
+        supported_configurations: ['DD_SERVICE']
+      )
+    end
+
+    it 'returns the source environment as a Hash' do
+      expect(subject.to_h).to eq('DD_SERVICE' => 'my-app', 'PATH' => '/usr/bin')
+    end
+  end
+
   describe '#get_environment_variable' do
     context 'when using default source_env' do
       subject do
diff --git a/spec/datadog/core/environment/identity_spec.rb b/spec/datadog/core/environment/identity_spec.rb
index 349481977f..749f78ee9a 100644
--- a/spec/datadog/core/environment/identity_spec.rb
+++ b/spec/datadog/core/environment/identity_spec.rb
@@ -34,6 +34,48 @@
     end
   end
 
+  describe '::root_runtime_id' do
+    subject(:root_runtime_id) { described_class.root_runtime_id }
+
+    context 'in root process' do
+      it { is_expected.to be_nil }
+    end
+
+    context 'when invoked in a fork' do
+      before { skip 'Fork not supported on current platform' unless Process.respond_to?(:fork) }
+
+      it 'equals the parent id' do
+        parent_id = described_class.id
+
+        expect_in_fork do
+          described_class.id # Triggers after_fork! update
+          expect(described_class.root_runtime_id).to eq(parent_id)
+        end
+      end
+    end
+  end
+
+  describe '::parent_runtime_id' do
+    subject(:parent_runtime_id) { described_class.parent_runtime_id }
+
+    context 'in root process' do
+      it { is_expected.to be_nil }
+    end
+
+    context 'when invoked in a fork' do
+      before { skip 'Fork not supported on current platform' unless Process.respond_to?(:fork) }
+
+      it 'equals the parent id' do
+        parent_id = described_class.id
+
+        expect_in_fork do
+          described_class.id # Triggers after_fork! update
+          expect(described_class.parent_runtime_id).to eq(parent_id)
+        end
+      end
+    end
+  end
+
   describe '::lang' do
     subject(:lang) { described_class.lang }
 
diff --git a/spec/datadog/core/utils/spawn_monkey_patch_spec.rb b/spec/datadog/core/utils/spawn_monkey_patch_spec.rb
new file mode 100644
index 0000000000..860af2e0fc
--- /dev/null
+++ b/spec/datadog/core/utils/spawn_monkey_patch_spec.rb
@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+
+require 'datadog/core/utils/spawn_monkey_patch'
+require 'datadog/core/configuration/components'
+require 'datadog/core/configuration/settings'
+
+RSpec.describe Datadog::Core::Utils::SpawnMonkeyPatch do
+  describe '::apply!' do
+    subject(:apply!) { described_class.apply! }
+
+    context 'when Process.spawn is supported' do
+      before do
+        skip 'Fork not supported' unless Process.respond_to?(:fork)
+        skip 'Process.spawn not supported' unless Process.respond_to?(:spawn)
+      end
+
+      it 'prepends the spawn monkey patch' do
+        expect_in_fork do
+          apply!
+          expect(Process.singleton_class.ancestors).to include(described_class::ProcessSpawnPatch)
+          expect(Process.method(:spawn).source_location.first).to match(/spawn_monkey_patch\.rb/)
+        end
+      end
+    end
+  end
+
+  describe 'Components initialization' do
+    reset_at_fork_monkey_patch_for_components!
+
+    before do
+      skip 'Fork not supported' unless Process.respond_to?(:fork)
+      skip 'Process.spawn not supported' unless Process.respond_to?(:spawn)
+    end
+
+    it 'applies both fork and spawn patches when Components is initialized' do
+      expect_in_fork do
+        Datadog::Core::Configuration::Components.new(Datadog::Core::Configuration::Settings.new)
+
+        expect(Process.singleton_class.ancestors).to include(
+          Datadog::Core::Utils::AtForkMonkeyPatch::ProcessMonkeyPatch,
+        )
+        expect(Process.singleton_class.ancestors).to include(
+          Datadog::Core::Utils::SpawnMonkeyPatch::ProcessSpawnPatch,
+        )
+      end
+    end
+  end
+end

From 8e2e7dab94519de881c3013adaf83a6e2fdb53bc Mon Sep 17 00:00:00 2001
From: Munir <munir.abdinur@datadoghq.com>
Date: Mon, 23 Mar 2026 16:40:21 -0400
Subject: [PATCH 07/10] fix steep

---
 .../core/configuration/config_helper.rbs      |  2 ++
 sig/datadog/core/environment/identity.rbs     |  6 ++++++
 sig/datadog/core/utils/spawn_monkey_patch.rbs | 19 +++++++++----------
 3 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/sig/datadog/core/configuration/config_helper.rbs b/sig/datadog/core/configuration/config_helper.rbs
index 77fb203915..db20b4f874 100644
--- a/sig/datadog/core/configuration/config_helper.rbs
+++ b/sig/datadog/core/configuration/config_helper.rbs
@@ -24,6 +24,8 @@ module Datadog
 
         def key?: (String name) -> bool
 
+        def to_h: () -> Hash[::String, ::String]
+
         alias has_key? key?
         alias include? key?
         alias member? key?
diff --git a/sig/datadog/core/environment/identity.rbs b/sig/datadog/core/environment/identity.rbs
index 5644841f0a..31ba8d04c3 100644
--- a/sig/datadog/core/environment/identity.rbs
+++ b/sig/datadog/core/environment/identity.rbs
@@ -6,6 +6,12 @@ module Datadog
 
         def self?.id: () -> ::String
 
+        def self?.root_runtime_id: () -> ::String?
+
+        def self?.parent_runtime_id: () -> ::String?
+
+        def self?.runtime_propagation_envs: () -> Hash[::String, ::String]
+
         def self?.lang: () -> ::String
 
         def self?.lang_engine: () -> ::String
diff --git a/sig/datadog/core/utils/spawn_monkey_patch.rbs b/sig/datadog/core/utils/spawn_monkey_patch.rbs
index e640e63869..52fa113139 100644
--- a/sig/datadog/core/utils/spawn_monkey_patch.rbs
+++ b/sig/datadog/core/utils/spawn_monkey_patch.rbs
@@ -1,15 +1,14 @@
 module Datadog
-    module Core
-      module Utils
-        module SpawnMonkeyPatch
-          def self.apply!: () -> (false | true)
-  
-          module ProcessSpawnPatch
-            def spawn: (*untyped args, **untyped opts) -> untyped
-          end
-  
-          def self.inject_lineage_envs: (untyped args) -> untyped
+  module Core
+    module Utils
+      module SpawnMonkeyPatch
+        def self.apply!: () -> (false | true)
+
+        module ProcessSpawnPatch
+          def spawn: (*untyped args, **untyped opts) -> untyped
         end
+
+        def self.inject_lineage_envs: (untyped args) -> untyped
       end
     end
   end

From e2b2a892b551937a770e19c80be4919410e5b12b Mon Sep 17 00:00:00 2001
From: Munir <munir.abdinur@datadoghq.com>
Date: Mon, 23 Mar 2026 16:51:07 -0400
Subject: [PATCH 08/10] avoid fixing circular import in this PR

---
 lib/datadog/core.rb                      | 10 +---------
 lib/datadog/core/configuration.rb        |  4 ++++
 lib/datadog/core/environment/identity.rb |  5 +++--
 lib/datadog/tracing/tracer.rb            |  1 -
 4 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/lib/datadog/core.rb b/lib/datadog/core.rb
index e438bfe68f..84bfc7ae30 100644
--- a/lib/datadog/core.rb
+++ b/lib/datadog/core.rb
@@ -2,16 +2,7 @@
 
 require_relative 'core/deprecations'
 require_relative 'core/configuration/config_helper'
-
-# DATADOG_ENV must be defined before requiring extensions, because extensions loads
-# components (via configuration), which loads spawn_monkey_patch, which loads identity;
-# identity uses DATADOG_ENV at load time.
-module Datadog
-  DATADOG_ENV = Core::Configuration::ConfigHelper.new
-end
-
 require_relative 'core/extensions'
-
 # We must load core extensions to make certain global APIs
 # accessible: both for Datadog features and the core itself.
 module Datadog
@@ -30,6 +21,7 @@ module Core
       end
   end
 
+  DATADOG_ENV = Core::Configuration::ConfigHelper.new
   extend Core::Extensions
 
   # Add shutdown hook:
diff --git a/lib/datadog/core/configuration.rb b/lib/datadog/core/configuration.rb
index 427633c5f7..4ced087d7a 100644
--- a/lib/datadog/core/configuration.rb
+++ b/lib/datadog/core/configuration.rb
@@ -1,5 +1,9 @@
 # frozen_string_literal: true
 
+# Products that require core/configuration directly (e.g. datadog/open_feature) bypass core.rb.
+# Ensure DATADOG_ENV exists so Identity and other modules that use it at load time work.
+require_relative '../core' unless defined?(::Datadog::DATADOG_ENV)
+
 require_relative 'configuration/components'
 require_relative 'configuration/settings'
 require_relative 'telemetry/emitter'
diff --git a/lib/datadog/core/environment/identity.rb b/lib/datadog/core/environment/identity.rb
index 1230f02620..5b34c8f732 100644
--- a/lib/datadog/core/environment/identity.rb
+++ b/lib/datadog/core/environment/identity.rb
@@ -18,8 +18,9 @@ module Identity
 
         module_function
 
-        @root_runtime_id = DATADOG_ENV[ENV_ROOT_SESSION_ID]&.freeze
-        @parent_runtime_id = DATADOG_ENV[ENV_PARENT_SESSION_ID]&.freeze
+        env = defined?(::Datadog::DATADOG_ENV) ? ::Datadog::DATADOG_ENV : ENV # rubocop:disable CustomCops/EnvUsageCop
+        @root_runtime_id = env[ENV_ROOT_SESSION_ID]&.freeze
+        @parent_runtime_id = env[ENV_PARENT_SESSION_ID]&.freeze
 
         def id
           @id ||= ::SecureRandom.uuid.freeze
diff --git a/lib/datadog/tracing/tracer.rb b/lib/datadog/tracing/tracer.rb
index dd9ab6404a..637f30575f 100644
--- a/lib/datadog/tracing/tracer.rb
+++ b/lib/datadog/tracing/tracer.rb
@@ -1,6 +1,5 @@
 # frozen_string_literal: true
 
-require_relative '../core'
 require_relative '../core/environment/ext'
 require_relative '../core/environment/socket'
 

From 319995f577b5fe9452273d8874e1db5ec869ea7e Mon Sep 17 00:00:00 2001
From: Munir <munir.abdinur@datadoghq.com>
Date: Mon, 23 Mar 2026 16:53:10 -0400
Subject: [PATCH 09/10] avoid fixing circular import in this PR

---
 lib/datadog/core.rb               | 1 +
 lib/datadog/core/configuration.rb | 4 ----
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/lib/datadog/core.rb b/lib/datadog/core.rb
index 84bfc7ae30..d178cbd2f8 100644
--- a/lib/datadog/core.rb
+++ b/lib/datadog/core.rb
@@ -3,6 +3,7 @@
 require_relative 'core/deprecations'
 require_relative 'core/configuration/config_helper'
 require_relative 'core/extensions'
+
 # We must load core extensions to make certain global APIs
 # accessible: both for Datadog features and the core itself.
 module Datadog
diff --git a/lib/datadog/core/configuration.rb b/lib/datadog/core/configuration.rb
index 4ced087d7a..427633c5f7 100644
--- a/lib/datadog/core/configuration.rb
+++ b/lib/datadog/core/configuration.rb
@@ -1,9 +1,5 @@
 # frozen_string_literal: true
 
-# Products that require core/configuration directly (e.g. datadog/open_feature) bypass core.rb.
-# Ensure DATADOG_ENV exists so Identity and other modules that use it at load time work.
-require_relative '../core' unless defined?(::Datadog::DATADOG_ENV)
-
 require_relative 'configuration/components'
 require_relative 'configuration/settings'
 require_relative 'telemetry/emitter'

From 2751bebb5593035bae80230a37a3bc54916ef505 Mon Sep 17 00:00:00 2001
From: Munir <munir.abdinur@datadoghq.com>
Date: Tue, 24 Mar 2026 13:26:47 -0400
Subject: [PATCH 10/10] clean ups from PR review

---
 lib/datadog/core/configuration/components.rb  |  5 +++-
 lib/datadog/core/utils/spawn_monkey_patch.rb  | 26 +++++++++----------
 sig/datadog/core/environment/identity.rbs     |  2 +-
 sig/datadog/core/utils/spawn_monkey_patch.rbs |  9 ++++---
 .../datadog/core/environment/identity_spec.rb | 10 ++++---
 .../core/utils/spawn_monkey_patch_spec.rb     |  2 +-
 6 files changed, 30 insertions(+), 24 deletions(-)

diff --git a/lib/datadog/core/configuration/components.rb b/lib/datadog/core/configuration/components.rb
index 099ca015e6..9a18221328 100644
--- a/lib/datadog/core/configuration/components.rb
+++ b/lib/datadog/core/configuration/components.rb
@@ -23,6 +23,7 @@
 require_relative '../../error_tracking/component'
 require_relative '../crashtracking/component'
 require_relative '../environment/agent_info'
+require_relative '../environment/identity'
 require_relative '../process_discovery'
 require_relative '../../data_streams/processor'
 
@@ -131,7 +132,9 @@ def initialize(settings)
           # Register fork handling once globally
           self.class::PATCH_ONLY_ONCE.run do
             Utils::AtForkMonkeyPatch.apply!
-            Utils::SpawnMonkeyPatch.apply!
+            Utils::SpawnMonkeyPatch.apply!(
+              lineage_envs_provider: Core::Environment::Identity.method(:runtime_propagation_envs),
+            )
 
             # Register callback that calls Components.after_fork
             Utils::AtForkMonkeyPatch.at_fork(:child) do
diff --git a/lib/datadog/core/utils/spawn_monkey_patch.rb b/lib/datadog/core/utils/spawn_monkey_patch.rb
index 9bbf1d5f33..53af685130 100644
--- a/lib/datadog/core/utils/spawn_monkey_patch.rb
+++ b/lib/datadog/core/utils/spawn_monkey_patch.rb
@@ -1,12 +1,12 @@
 # frozen_string_literal: true
 
-require_relative '../environment/identity'
-
 module Datadog
   module Core
     module Utils
       module SpawnMonkeyPatch
-        def self.apply!
+        # @param lineage_envs_provider [#call] returns a Hash of env vars to merge into the child process
+        def self.apply!(lineage_envs_provider:)
+          @lineage_envs_provider = lineage_envs_provider
           ::Process.singleton_class.prepend(ProcessSpawnPatch)
           true
         end
@@ -18,19 +18,17 @@ def spawn(*args, **opts)
           end
         end
 
-        class << self
-          # Process.spawn(env?, cmd, ...): env is optional first arg (Hash). When present, merge
-          # runtime_ids into it; when absent, prepend full ENV + runtime_ids so the child inherits both.
-          def inject_lineage_envs(args)
-            runtime_ids = Core::Environment::Identity.runtime_propagation_envs
-            env_provided = Hash === args.first
+        # Process.spawn(env?, cmd, ...): env is optional first arg (Hash). When present, merge
+        # runtime_ids into it; when absent, prepend full ENV + runtime_ids so the child inherits both.
+        def self.inject_lineage_envs(args)
+          runtime_ids = @lineage_envs_provider.call
+          env_provided = Hash === args.first
 
-            base_env = env_provided ? args.first : DATADOG_ENV.to_h
-            env = base_env.merge(runtime_ids)
-            rest = env_provided ? args.drop(1) : args
+          base_env = env_provided ? args.first : DATADOG_ENV.to_h
+          env = base_env.merge(runtime_ids)
+          rest = env_provided ? args.drop(1) : args
 
-            [env, *rest]
-          end
+          [env, *rest]
         end
       end
     end
diff --git a/sig/datadog/core/environment/identity.rbs b/sig/datadog/core/environment/identity.rbs
index 31ba8d04c3..dcf4036375 100644
--- a/sig/datadog/core/environment/identity.rbs
+++ b/sig/datadog/core/environment/identity.rbs
@@ -10,7 +10,7 @@ module Datadog
 
         def self?.parent_runtime_id: () -> ::String?
 
-        def self?.runtime_propagation_envs: () -> Hash[::String, ::String]
+        def self?.runtime_propagation_envs: () -> ::Hash[::String, ::String]
 
         def self?.lang: () -> ::String
 
diff --git a/sig/datadog/core/utils/spawn_monkey_patch.rbs b/sig/datadog/core/utils/spawn_monkey_patch.rbs
index 52fa113139..4dbcceb490 100644
--- a/sig/datadog/core/utils/spawn_monkey_patch.rbs
+++ b/sig/datadog/core/utils/spawn_monkey_patch.rbs
@@ -2,14 +2,17 @@ module Datadog
   module Core
     module Utils
       module SpawnMonkeyPatch
-        def self.apply!: () -> (false | true)
+        # Set in apply! before Process.spawn is intercepted; internal wiring only.
+        self.@lineage_envs_provider: ^() -> ::Hash[::String, ::String]
+
+        def self.apply!: (lineage_envs_provider: ^() -> ::Hash[::String, ::String]) -> true
 
         module ProcessSpawnPatch
           def spawn: (*untyped args, **untyped opts) -> untyped
         end
 
-        def self.inject_lineage_envs: (untyped args) -> untyped
+        def self.inject_lineage_envs: (untyped args) -> ::Array[untyped]
       end
     end
   end
-end
\ No newline at end of file
+end
diff --git a/spec/datadog/core/environment/identity_spec.rb b/spec/datadog/core/environment/identity_spec.rb
index 749f78ee9a..4f21bfd985 100644
--- a/spec/datadog/core/environment/identity_spec.rb
+++ b/spec/datadog/core/environment/identity_spec.rb
@@ -34,7 +34,7 @@
     end
   end
 
-  describe '::root_runtime_id' do
+  describe '.root_runtime_id' do
     subject(:root_runtime_id) { described_class.root_runtime_id }
 
     context 'in root process' do
@@ -48,14 +48,16 @@
         parent_id = described_class.id
 
         expect_in_fork do
-          described_class.id # Triggers after_fork! update
+          expect(described_class.id).to_not be_nil
+          expect(described_class.root_runtime_id).to_not be_nil
+          expect(described_class.id).to_not eq(root_runtime_id)
           expect(described_class.root_runtime_id).to eq(parent_id)
         end
       end
     end
   end
 
-  describe '::parent_runtime_id' do
+  describe '.parent_runtime_id' do
     subject(:parent_runtime_id) { described_class.parent_runtime_id }
 
     context 'in root process' do
@@ -69,7 +71,7 @@
         parent_id = described_class.id
 
         expect_in_fork do
-          described_class.id # Triggers after_fork! update
+          expect(described_class.id).to_not eq(parent_id)
           expect(described_class.parent_runtime_id).to eq(parent_id)
         end
       end
diff --git a/spec/datadog/core/utils/spawn_monkey_patch_spec.rb b/spec/datadog/core/utils/spawn_monkey_patch_spec.rb
index 860af2e0fc..9946cded10 100644
--- a/spec/datadog/core/utils/spawn_monkey_patch_spec.rb
+++ b/spec/datadog/core/utils/spawn_monkey_patch_spec.rb
@@ -6,7 +6,7 @@
 
 RSpec.describe Datadog::Core::Utils::SpawnMonkeyPatch do
   describe '::apply!' do
-    subject(:apply!) { described_class.apply! }
+    subject(:apply!) { described_class.apply!(lineage_envs_provider: -> { {} }) }
 
     context 'when Process.spawn is supported' do
       before do