diff --git a/recipe_modules/adhoc_validation/__init__.py b/recipe_modules/adhoc_validation/__init__.py
index 588adc5..f65b98d 100644
--- a/recipe_modules/adhoc_validation/__init__.py
+++ b/recipe_modules/adhoc_validation/__init__.py
@@ -1,10 +1,10 @@
 PYTHON_VERSION_COMPATIBILITY = 'PY3'
 
 DEPS = [
-    'depot_tools/osx_sdk',
     'flutter/firebase',
     'flutter/flutter_deps',
     'flutter/kms',
+    'flutter/osx_sdk',
     'flutter/repo_util',
     'flutter/test_utils',
     'recipe_engine/context',
diff --git a/recipe_modules/adhoc_validation/examples/full.expected/mac.json b/recipe_modules/adhoc_validation/examples/full.expected/mac.json
index c34606e..d3ac166 100644
--- a/recipe_modules/adhoc_validation/examples/full.expected/mac.json
+++ b/recipe_modules/adhoc_validation/examples/full.expected/mac.json
@@ -39,7 +39,7 @@
       "-root",
       "[CACHE]/osx_sdk",
       "-ensure-file",
-      "infra/tools/mac_toolchain/${platform} git_revision:723fc1a6c8cdf2631a57851f5610e598db0c1de1",
+      "infra/tools/mac_toolchain/${platform} latest",
       "-max-threads",
       "0",
       "-json-output",
@@ -70,7 +70,7 @@
       "@@@STEP_LOG_LINE@json.output@  \"result\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"\": [@@@",
       "@@@STEP_LOG_LINE@json.output@      {@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"instance_id\": \"resolved-instance_id-of-git_revision:723\", @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"instance_id\": \"resolved-instance_id-of-latest----------\", @@@",
       "@@@STEP_LOG_LINE@json.output@        \"package\": \"infra/tools/mac_toolchain/resolved-platform\"@@@",
       "@@@STEP_LOG_LINE@json.output@      }@@@",
       "@@@STEP_LOG_LINE@json.output@    ]@@@",
@@ -88,7 +88,9 @@
       "-xcode-version",
       "9f2000",
       "-output-dir",
-      "[CACHE]/osx_sdk/XCode.app"
+      "[CACHE]/osx_sdk/XCode.app",
+      "-cipd-package-prefix",
+      "flutter_internal/ios/xcode"
     ],
     "env": {
       "DEPOT_TOOLS": "RECIPE_REPO[depot_tools]",
@@ -145,6 +147,35 @@
   },
   {
     "cmd": [
+      "xcrun",
+      "simctl",
+      "list"
+    ],
+    "env": {
+      "DEPOT_TOOLS": "RECIPE_REPO[depot_tools]",
+      "GIT_BRANCH": "",
+      "LUCI_BRANCH": "",
+      "LUCI_CI": "True",
+      "LUCI_PR": "",
+      "OS": "darwin",
+      "PUB_CACHE": "[START_DIR]/.pub-cache",
+      "REVISION": "",
+      "SDK_CHECKOUT_PATH": "[START_DIR]/flutter sdk"
+    },
+    "env_prefixes": {
+      "PATH": [
+        "[START_DIR]/flutter sdk/bin",
+        "[START_DIR]/flutter sdk/bin/cache/dart-sdk/bin"
+      ]
+    },
+    "infra_step": true,
+    "name": "Docs.list simulators",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
       "RECIPE_MODULE[flutter::adhoc_validation]/resources/docs.sh"
     ],
     "env": {
diff --git a/recipes/engine/engine_builder.py b/recipes/engine/engine_builder.py
index 2254c54..07c9ee3 100644
--- a/recipes/engine/engine_builder.py
+++ b/recipes/engine/engine_builder.py
@@ -11,8 +11,8 @@
 
 DEPS = [
   'depot_tools/depot_tools',
-  'depot_tools/osx_sdk',
   'flutter/os_utils',
+  'flutter/osx_sdk',
   'flutter/repo_util',
   'flutter/shard_util_v2',
   'fuchsia/goma',
diff --git a/recipes/engine/web_engine_drone.expected/mac-post-submit.json b/recipes/engine/web_engine_drone.expected/mac-post-submit.json
index 0da84bc..50bc0dc 100644
--- a/recipes/engine/web_engine_drone.expected/mac-post-submit.json
+++ b/recipes/engine/web_engine_drone.expected/mac-post-submit.json
@@ -405,7 +405,7 @@
       "-root",
       "[CACHE]/osx_sdk",
       "-ensure-file",
-      "infra/tools/mac_toolchain/${platform} git_revision:723fc1a6c8cdf2631a57851f5610e598db0c1de1",
+      "infra/tools/mac_toolchain/${platform} latest",
       "-max-threads",
       "0",
       "-json-output",
@@ -442,7 +442,7 @@
       "@@@STEP_LOG_LINE@json.output@  \"result\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"\": [@@@",
       "@@@STEP_LOG_LINE@json.output@      {@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"instance_id\": \"resolved-instance_id-of-git_revision:723\", @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"instance_id\": \"resolved-instance_id-of-latest----------\", @@@",
       "@@@STEP_LOG_LINE@json.output@        \"package\": \"infra/tools/mac_toolchain/resolved-platform\"@@@",
       "@@@STEP_LOG_LINE@json.output@      }@@@",
       "@@@STEP_LOG_LINE@json.output@    ]@@@",
@@ -460,7 +460,9 @@
       "-xcode-version",
       "9f2000",
       "-output-dir",
-      "[CACHE]/osx_sdk/XCode.app"
+      "[CACHE]/osx_sdk/XCode.app",
+      "-cipd-package-prefix",
+      "flutter_internal/ios/xcode"
     ],
     "cwd": "[CLEANUP]/builder/src/flutter/lib/web_ui",
     "env": {
@@ -525,6 +527,39 @@
   },
   {
     "cmd": [
+      "xcrun",
+      "simctl",
+      "list"
+    ],
+    "cwd": "[CLEANUP]/builder/src/flutter/lib/web_ui",
+    "env": {
+      "ANDROID_HOME": "[CLEANUP]/builder/src/third_party/android_tools/sdk",
+      "CHROME_NO_SANDBOX": "true",
+      "ENGINE_PATH": "[CLEANUP]/builder",
+      "GOMA_DIR": "[CACHE]/goma/client",
+      "LOCAL_ENGINE": "[CLEANUP]/builder/src/out/host_debug_unopt"
+    },
+    "env_prefixes": {
+      "PATH": [
+        "[CLEANUP]/builder/src/third_party/dart/tools/sdks/dart-sdk/bin",
+        "[CLEANUP]/builder/src/out/host_debug_unopt/dart-sdk/bin"
+      ]
+    },
+    "env_suffixes": {
+      "DEPOT_TOOLS_UPDATE": [
+        "0",
+        "0"
+      ],
+      "PATH": [
+        "RECIPE_REPO[depot_tools]",
+        "RECIPE_REPO[depot_tools]"
+      ]
+    },
+    "infra_step": true,
+    "name": "list simulators"
+  },
+  {
+    "cmd": [
       "[CLEANUP]/builder/src/out/host_debug_unopt/dart-sdk/bin/dart",
       "dev/felt.dart",
       "test",
diff --git a/recipes/engine/web_engine_drone.py b/recipes/engine/web_engine_drone.py
index 9156c0f..dcdb764 100644
--- a/recipes/engine/web_engine_drone.py
+++ b/recipes/engine/web_engine_drone.py
@@ -23,9 +23,9 @@
 
 DEPS = [
     'depot_tools/depot_tools',
-    'depot_tools/osx_sdk',
     'flutter/flutter_deps',
     'flutter/os_utils',
+    'flutter/osx_sdk',
     'flutter/repo_util',
     'flutter/retry',
     'flutter/web_util',
diff --git a/recipes/ios-usb-dependencies.py b/recipes/ios-usb-dependencies.py
index 74c8e45..1bf25fb 100644
--- a/recipes/ios-usb-dependencies.py
+++ b/recipes/ios-usb-dependencies.py
@@ -8,7 +8,7 @@
 
 DEPS = [
     'depot_tools/gsutil',
-    'depot_tools/osx_sdk',
+    'flutter/osx_sdk',
     'flutter/zip',
     'recipe_engine/buildbucket',
     'recipe_engine/file',