diff --git a/recipes/engine_v2/engine_v2.expected/basic_linux.json b/recipes/engine_v2/engine_v2.expected/basic_linux.json
index 8a3ccb3..c77ada2 100644
--- a/recipes/engine_v2/engine_v2.expected/basic_linux.json
+++ b/recipes/engine_v2/engine_v2.expected/basic_linux.json
@@ -1,200 +1,6 @@
 [
   {
     "cmd": [],
-    "name": "Checkout flutter/engine"
-  },
-  {
-    "cmd": [
-      "python3",
-      "-u",
-      "RECIPE_MODULE[depot_tools::git]/resources/git_setup.py",
-      "--path",
-      "[START_DIR]/engine",
-      "--url",
-      "https://flutter.googlesource.com/mirrors/engine"
-    ],
-    "luci_context": {
-      "realm": {
-        "name": "proj:try"
-      },
-      "resultdb": {
-        "current_invocation": {
-          "name": "invocations/build:8945511751514863184",
-          "update_token": "token"
-        },
-        "hostname": "rdbhost"
-      }
-    },
-    "name": "Checkout flutter/engine.git setup",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "git",
-      "fetch",
-      "origin",
-      "--recurse-submodules",
-      "--progress",
-      "--tags"
-    ],
-    "cwd": "[START_DIR]/engine",
-    "env": {
-      "PATH": "RECIPE_REPO[depot_tools]:<PATH>"
-    },
-    "infra_step": true,
-    "luci_context": {
-      "realm": {
-        "name": "proj:try"
-      },
-      "resultdb": {
-        "current_invocation": {
-          "name": "invocations/build:8945511751514863184",
-          "update_token": "token"
-        },
-        "hostname": "rdbhost"
-      }
-    },
-    "name": "Checkout flutter/engine.git fetch",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "git",
-      "checkout",
-      "-f",
-      "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
-    ],
-    "cwd": "[START_DIR]/engine",
-    "infra_step": true,
-    "luci_context": {
-      "realm": {
-        "name": "proj:try"
-      },
-      "resultdb": {
-        "current_invocation": {
-          "name": "invocations/build:8945511751514863184",
-          "update_token": "token"
-        },
-        "hostname": "rdbhost"
-      }
-    },
-    "name": "Checkout flutter/engine.git checkout",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "git",
-      "rev-parse",
-      "HEAD"
-    ],
-    "cwd": "[START_DIR]/engine",
-    "infra_step": true,
-    "luci_context": {
-      "realm": {
-        "name": "proj:try"
-      },
-      "resultdb": {
-        "current_invocation": {
-          "name": "invocations/build:8945511751514863184",
-          "update_token": "token"
-        },
-        "hostname": "rdbhost"
-      }
-    },
-    "name": "Checkout flutter/engine.read revision",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_TEXT@<br/>checked out 'deadbeef'<br/>@@@",
-      "@@@SET_BUILD_PROPERTY@got_revision@\"deadbeef\"@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "git",
-      "clean",
-      "-f",
-      "-d",
-      "-x"
-    ],
-    "cwd": "[START_DIR]/engine",
-    "infra_step": true,
-    "luci_context": {
-      "realm": {
-        "name": "proj:try"
-      },
-      "resultdb": {
-        "current_invocation": {
-          "name": "invocations/build:8945511751514863184",
-          "update_token": "token"
-        },
-        "hostname": "rdbhost"
-      }
-    },
-    "name": "Checkout flutter/engine.git clean",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "git",
-      "submodule",
-      "sync"
-    ],
-    "cwd": "[START_DIR]/engine",
-    "infra_step": true,
-    "luci_context": {
-      "realm": {
-        "name": "proj:try"
-      },
-      "resultdb": {
-        "current_invocation": {
-          "name": "invocations/build:8945511751514863184",
-          "update_token": "token"
-        },
-        "hostname": "rdbhost"
-      }
-    },
-    "name": "Checkout flutter/engine.submodule sync",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "git",
-      "submodule",
-      "update",
-      "--init",
-      "--recursive"
-    ],
-    "cwd": "[START_DIR]/engine",
-    "infra_step": true,
-    "luci_context": {
-      "realm": {
-        "name": "proj:try"
-      },
-      "resultdb": {
-        "current_invocation": {
-          "name": "invocations/build:8945511751514863184",
-          "update_token": "token"
-        },
-        "hostname": "rdbhost"
-      }
-    },
-    "name": "Checkout flutter/engine.submodule update",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@"
-    ]
-  },
-  {
-    "cmd": [],
     "name": "launch builds"
   },
   {
@@ -218,7 +24,7 @@
       }
     },
     "name": "launch builds.schedule",
-    "stdin": "{\"requests\": [{\"scheduleBuild\": {\"builder\": {\"bucket\": \"try\", \"builder\": \"Linux Staging Engine Drone\", \"project\": \"proj\"}, \"exe\": {\"cipdVersion\": \"refs/heads/main\"}, \"experimental\": \"NO\", \"experiments\": {\"luci.buildbucket.parent_tracking\": false}, \"fields\": \"builder,createTime,createdBy,critical,endTime,id,infra,input,number,output,startTime,status,updateTime\", \"gerritChanges\": [{\"change\": \"123456\", \"host\": \"flutter-review.googlesource.com\", \"patchset\": \"7\", \"project\": \"mirrors/engine\"}], \"gitilesCommit\": {\"host\": \"flutter.googlesource.com\", \"id\": \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\", \"project\": \"mirrors/engine\", \"ref\": \"refs/heads/main\"}, \"priority\": 25, \"properties\": {\"build\": {\"generators\": [{\"name\": \"generator1\", \"script\": \"script1.sh\"}], \"gn\": [\"--ios\"], \"name\": \"ios_debug\", \"ninja\": {\"config\": \"ios_debug\", \"targets\": []}}, \"builds\": [{\"generators\": [{\"name\": \"generator1\", \"script\": \"script1.sh\"}], \"gn\": [\"--ios\"], \"name\": \"ios_debug\", \"ninja\": {\"config\": \"ios_debug\", \"targets\": []}}], \"environment\": \"Staging\", \"generators\": {\"tasks\": [{\"language\": \"python\", \"name\": \"Debug-FlutterMacOS.framework\", \"parameters\": [\"--variant\", \"host_profile\", \"--type\", \"engine\", \"--engine-capture-core-dump\"], \"script\": \"flutter/sky/tools/create_macos_framework.py\", \"type\": \"local\"}]}, \"recipe\": \"engine_v2/builder\", \"tests\": []}, \"requestId\": \"8945511751514863184-00000000-0000-0000-0000-000000001337\", \"swarming\": {\"parentRunId\": \"fake-task-id\"}, \"tags\": [{\"key\": \"cq_experimental\", \"value\": \"false\"}, {\"key\": \"parent_buildbucket_id\", \"value\": \"8945511751514863184\"}, {\"key\": \"user_agent\", \"value\": \"recipe\"}]}}]}",
+    "stdin": "{\"requests\": [{\"scheduleBuild\": {\"builder\": {\"bucket\": \"try\", \"builder\": \"Linux Staging Engine Drone\", \"project\": \"proj\"}, \"exe\": {\"cipdVersion\": \"refs/heads/main\"}, \"experimental\": \"NO\", \"experiments\": {\"luci.buildbucket.parent_tracking\": false}, \"fields\": \"builder,createTime,createdBy,critical,endTime,id,infra,input,number,output,startTime,status,updateTime\", \"gerritChanges\": [{\"change\": \"123456\", \"host\": \"flutter-review.googlesource.com\", \"patchset\": \"7\", \"project\": \"mirrors/engine\"}], \"gitilesCommit\": {\"host\": \"flutter.googlesource.com\", \"id\": \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\", \"project\": \"mirrors/engine\", \"ref\": \"refs/heads/main\"}, \"priority\": 25, \"properties\": {\"build\": {\"generators\": [{\"name\": \"generator1\", \"script\": \"script1.sh\"}], \"gn\": [\"--ios\"], \"name\": \"ios_debug\", \"ninja\": {\"config\": \"ios_debug\", \"targets\": []}}, \"builds\": [{\"generators\": [{\"name\": \"generator1\", \"script\": \"script1.sh\"}], \"gn\": [\"--ios\"], \"name\": \"ios_debug\", \"ninja\": {\"config\": \"ios_debug\", \"targets\": []}}], \"environment\": \"Staging\", \"generators\": {\"tasks\": [{\"language\": \"python\", \"name\": \"Debug-FlutterMacOS.framework\", \"parameters\": [\"--variant\", \"host_profile\", \"--type\", \"engine\", \"--engine-capture-core-dump\"], \"script\": \"flutter/sky/tools/create_macos_framework.py\", \"type\": \"local\"}]}, \"recipe\": \"engine_v2/builder\"}, \"requestId\": \"8945511751514863184-00000000-0000-0000-0000-000000001337\", \"swarming\": {\"parentRunId\": \"fake-task-id\"}, \"tags\": [{\"key\": \"cq_experimental\", \"value\": \"false\"}, {\"key\": \"parent_buildbucket_id\", \"value\": \"8945511751514863184\"}, {\"key\": \"user_agent\", \"value\": \"recipe\"}]}}]}",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -321,8 +127,7 @@
       "@@@STEP_LOG_LINE@request@              }@@@",
       "@@@STEP_LOG_LINE@request@            ]@@@",
       "@@@STEP_LOG_LINE@request@          }, @@@",
-      "@@@STEP_LOG_LINE@request@          \"recipe\": \"engine_v2/builder\", @@@",
-      "@@@STEP_LOG_LINE@request@          \"tests\": []@@@",
+      "@@@STEP_LOG_LINE@request@          \"recipe\": \"engine_v2/builder\"@@@",
       "@@@STEP_LOG_LINE@request@        }, @@@",
       "@@@STEP_LOG_LINE@request@        \"requestId\": \"8945511751514863184-00000000-0000-0000-0000-000000001337\", @@@",
       "@@@STEP_LOG_LINE@request@        \"swarming\": {@@@",
@@ -1055,32 +860,6 @@
     ]
   },
   {
-    "cmd": [
-      "python3",
-      "-u",
-      "RECIPE_MODULE[recipe_engine::json]/resources/read.py",
-      "[START_DIR]/engine/ci/builders/None.json",
-      "/path/to/tmp/json"
-    ],
-    "luci_context": {
-      "realm": {
-        "name": "proj:try"
-      },
-      "resultdb": {
-        "current_invocation": {
-          "name": "invocations/build:8945511751514863184",
-          "update_token": "token"
-        },
-        "hostname": "rdbhost"
-      }
-    },
-    "name": "Read build config file",
-    "~followup_annotations": [
-      "@@@STEP_LOG_LINE@json.output@{}@@@",
-      "@@@STEP_LOG_END@json.output@@@"
-    ]
-  },
-  {
     "name": "$result"
   }
 ]
\ No newline at end of file
diff --git a/recipes/engine_v2/engine_v2.expected/basic_mac.json b/recipes/engine_v2/engine_v2.expected/basic_mac.json
index 65db1fc..49c8b8f 100644
--- a/recipes/engine_v2/engine_v2.expected/basic_mac.json
+++ b/recipes/engine_v2/engine_v2.expected/basic_mac.json
@@ -1,200 +1,6 @@
 [
   {
     "cmd": [],
-    "name": "Checkout flutter/engine"
-  },
-  {
-    "cmd": [
-      "python3",
-      "-u",
-      "RECIPE_MODULE[depot_tools::git]/resources/git_setup.py",
-      "--path",
-      "[START_DIR]/engine",
-      "--url",
-      "https://flutter.googlesource.com/mirrors/engine"
-    ],
-    "luci_context": {
-      "realm": {
-        "name": "proj:try"
-      },
-      "resultdb": {
-        "current_invocation": {
-          "name": "invocations/build:8945511751514863184",
-          "update_token": "token"
-        },
-        "hostname": "rdbhost"
-      }
-    },
-    "name": "Checkout flutter/engine.git setup",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "git",
-      "fetch",
-      "origin",
-      "--recurse-submodules",
-      "--progress",
-      "--tags"
-    ],
-    "cwd": "[START_DIR]/engine",
-    "env": {
-      "PATH": "RECIPE_REPO[depot_tools]:<PATH>"
-    },
-    "infra_step": true,
-    "luci_context": {
-      "realm": {
-        "name": "proj:try"
-      },
-      "resultdb": {
-        "current_invocation": {
-          "name": "invocations/build:8945511751514863184",
-          "update_token": "token"
-        },
-        "hostname": "rdbhost"
-      }
-    },
-    "name": "Checkout flutter/engine.git fetch",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "git",
-      "checkout",
-      "-f",
-      "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
-    ],
-    "cwd": "[START_DIR]/engine",
-    "infra_step": true,
-    "luci_context": {
-      "realm": {
-        "name": "proj:try"
-      },
-      "resultdb": {
-        "current_invocation": {
-          "name": "invocations/build:8945511751514863184",
-          "update_token": "token"
-        },
-        "hostname": "rdbhost"
-      }
-    },
-    "name": "Checkout flutter/engine.git checkout",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "git",
-      "rev-parse",
-      "HEAD"
-    ],
-    "cwd": "[START_DIR]/engine",
-    "infra_step": true,
-    "luci_context": {
-      "realm": {
-        "name": "proj:try"
-      },
-      "resultdb": {
-        "current_invocation": {
-          "name": "invocations/build:8945511751514863184",
-          "update_token": "token"
-        },
-        "hostname": "rdbhost"
-      }
-    },
-    "name": "Checkout flutter/engine.read revision",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_TEXT@<br/>checked out 'deadbeef'<br/>@@@",
-      "@@@SET_BUILD_PROPERTY@got_revision@\"deadbeef\"@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "git",
-      "clean",
-      "-f",
-      "-d",
-      "-x"
-    ],
-    "cwd": "[START_DIR]/engine",
-    "infra_step": true,
-    "luci_context": {
-      "realm": {
-        "name": "proj:try"
-      },
-      "resultdb": {
-        "current_invocation": {
-          "name": "invocations/build:8945511751514863184",
-          "update_token": "token"
-        },
-        "hostname": "rdbhost"
-      }
-    },
-    "name": "Checkout flutter/engine.git clean",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "git",
-      "submodule",
-      "sync"
-    ],
-    "cwd": "[START_DIR]/engine",
-    "infra_step": true,
-    "luci_context": {
-      "realm": {
-        "name": "proj:try"
-      },
-      "resultdb": {
-        "current_invocation": {
-          "name": "invocations/build:8945511751514863184",
-          "update_token": "token"
-        },
-        "hostname": "rdbhost"
-      }
-    },
-    "name": "Checkout flutter/engine.submodule sync",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "git",
-      "submodule",
-      "update",
-      "--init",
-      "--recursive"
-    ],
-    "cwd": "[START_DIR]/engine",
-    "infra_step": true,
-    "luci_context": {
-      "realm": {
-        "name": "proj:try"
-      },
-      "resultdb": {
-        "current_invocation": {
-          "name": "invocations/build:8945511751514863184",
-          "update_token": "token"
-        },
-        "hostname": "rdbhost"
-      }
-    },
-    "name": "Checkout flutter/engine.submodule update",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@"
-    ]
-  },
-  {
-    "cmd": [],
     "name": "launch builds"
   },
   {
diff --git a/recipes/engine_v2/engine_v2.expected/config_from_file.json b/recipes/engine_v2/engine_v2.expected/config_from_file.json
index d290ae9..0c1d7c4 100644
--- a/recipes/engine_v2/engine_v2.expected/config_from_file.json
+++ b/recipes/engine_v2/engine_v2.expected/config_from_file.json
@@ -195,12 +195,16 @@
   },
   {
     "cmd": [
-      "python3",
+      "vpython3",
       "-u",
-      "RECIPE_MODULE[recipe_engine::json]/resources/read.py",
-      "[START_DIR]/engine/ci/builders/None.json",
-      "/path/to/tmp/json"
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "copy",
+      "[START_DIR]/engine/ci/builders/config_name.json",
+      "/path/to/tmp/"
     ],
+    "infra_step": true,
     "luci_context": {
       "realm": {
         "name": "proj:try"
@@ -215,27 +219,34 @@
     },
     "name": "Read build config file",
     "~followup_annotations": [
-      "@@@STEP_LOG_LINE@json.output@{@@@",
-      "@@@STEP_LOG_LINE@json.output@  \"builds\": [@@@",
-      "@@@STEP_LOG_LINE@json.output@    {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"generators\": [@@@",
-      "@@@STEP_LOG_LINE@json.output@        {@@@",
-      "@@@STEP_LOG_LINE@json.output@          \"name\": \"generator1\", @@@",
-      "@@@STEP_LOG_LINE@json.output@          \"script\": \"script1.sh\"@@@",
-      "@@@STEP_LOG_LINE@json.output@        }@@@",
-      "@@@STEP_LOG_LINE@json.output@      ], @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"gn\": [@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"--ios\"@@@",
-      "@@@STEP_LOG_LINE@json.output@      ], @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"name\": \"ios_debug\", @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"ninja\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"config\": \"ios_debug\", @@@",
-      "@@@STEP_LOG_LINE@json.output@        \"targets\": []@@@",
-      "@@@STEP_LOG_LINE@json.output@      }@@@",
-      "@@@STEP_LOG_LINE@json.output@    }@@@",
-      "@@@STEP_LOG_LINE@json.output@  ]@@@",
-      "@@@STEP_LOG_LINE@json.output@}@@@",
-      "@@@STEP_LOG_END@json.output@@@"
+      "@@@STEP_LOG_LINE@config_name.json@{@@@",
+      "@@@STEP_LOG_LINE@config_name.json@  \"archives\": [@@@",
+      "@@@STEP_LOG_LINE@config_name.json@    {@@@",
+      "@@@STEP_LOG_LINE@config_name.json@      \"destination\": \"bucket/c.txt\",@@@",
+      "@@@STEP_LOG_LINE@config_name.json@      \"name\": \"c.txt\",@@@",
+      "@@@STEP_LOG_LINE@config_name.json@      \"source\": \"/a/b/c.txt\"@@@",
+      "@@@STEP_LOG_LINE@config_name.json@    }@@@",
+      "@@@STEP_LOG_LINE@config_name.json@  ],@@@",
+      "@@@STEP_LOG_LINE@config_name.json@  \"builds\": [@@@",
+      "@@@STEP_LOG_LINE@config_name.json@    {@@@",
+      "@@@STEP_LOG_LINE@config_name.json@      \"generators\": [@@@",
+      "@@@STEP_LOG_LINE@config_name.json@        {@@@",
+      "@@@STEP_LOG_LINE@config_name.json@          \"name\": \"generator1\",@@@",
+      "@@@STEP_LOG_LINE@config_name.json@          \"script\": \"script1.sh\"@@@",
+      "@@@STEP_LOG_LINE@config_name.json@        }@@@",
+      "@@@STEP_LOG_LINE@config_name.json@      ],@@@",
+      "@@@STEP_LOG_LINE@config_name.json@      \"gn\": [@@@",
+      "@@@STEP_LOG_LINE@config_name.json@        \"--ios\"@@@",
+      "@@@STEP_LOG_LINE@config_name.json@      ],@@@",
+      "@@@STEP_LOG_LINE@config_name.json@      \"name\": \"ios_debug\",@@@",
+      "@@@STEP_LOG_LINE@config_name.json@      \"ninja\": {@@@",
+      "@@@STEP_LOG_LINE@config_name.json@        \"config\": \"ios_debug\",@@@",
+      "@@@STEP_LOG_LINE@config_name.json@        \"targets\": []@@@",
+      "@@@STEP_LOG_LINE@config_name.json@      }@@@",
+      "@@@STEP_LOG_LINE@config_name.json@    }@@@",
+      "@@@STEP_LOG_LINE@config_name.json@  ]@@@",
+      "@@@STEP_LOG_LINE@config_name.json@}@@@",
+      "@@@STEP_LOG_END@config_name.json@@@"
     ]
   },
   {
@@ -263,7 +274,7 @@
       }
     },
     "name": "launch builds.schedule",
-    "stdin": "{\"requests\": [{\"scheduleBuild\": {\"builder\": {\"bucket\": \"try\", \"builder\": \"Linux Staging Engine Drone\", \"project\": \"proj\"}, \"exe\": {\"cipdVersion\": \"refs/heads/main\"}, \"experimental\": \"NO\", \"experiments\": {\"luci.buildbucket.parent_tracking\": false}, \"fields\": \"builder,createTime,createdBy,critical,endTime,id,infra,input,number,output,startTime,status,updateTime\", \"gerritChanges\": [{\"change\": \"123456\", \"host\": \"github.com\", \"patchset\": \"7\", \"project\": \"repo/a\"}], \"gitilesCommit\": {\"host\": \"github.com\", \"id\": \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\", \"project\": \"repo/a\", \"ref\": \"refs/heads/main\"}, \"priority\": 25, \"properties\": {\"build\": {\"generators\": [{\"name\": \"generator1\", \"script\": \"script1.sh\"}], \"gn\": [\"--ios\"], \"name\": \"ios_debug\", \"ninja\": {\"config\": \"ios_debug\", \"targets\": []}}, \"environment\": \"Staging\", \"recipe\": \"engine_v2/builder\"}, \"requestId\": \"8945511751514863184-00000000-0000-0000-0000-000000001337\", \"swarming\": {\"parentRunId\": \"fake-task-id\"}, \"tags\": [{\"key\": \"cq_experimental\", \"value\": \"false\"}, {\"key\": \"parent_buildbucket_id\", \"value\": \"8945511751514863184\"}, {\"key\": \"user_agent\", \"value\": \"recipe\"}]}}]}",
+    "stdin": "{\"requests\": [{\"scheduleBuild\": {\"builder\": {\"bucket\": \"try\", \"builder\": \"Linux Staging Engine Drone\", \"project\": \"proj\"}, \"exe\": {\"cipdVersion\": \"refs/heads/main\"}, \"experimental\": \"NO\", \"experiments\": {\"luci.buildbucket.parent_tracking\": false}, \"fields\": \"builder,createTime,createdBy,critical,endTime,id,infra,input,number,output,startTime,status,updateTime\", \"gerritChanges\": [{\"change\": \"123456\", \"host\": \"flutter-review.googlesource.com\", \"patchset\": \"7\", \"project\": \"mirrors/engine\"}], \"gitilesCommit\": {\"host\": \"flutter.googlesource.com\", \"id\": \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\", \"project\": \"mirrors/engine\", \"ref\": \"refs/heads/main\"}, \"priority\": 25, \"properties\": {\"build\": {\"generators\": [{\"name\": \"generator1\", \"script\": \"script1.sh\"}], \"gn\": [\"--ios\"], \"name\": \"ios_debug\", \"ninja\": {\"config\": \"ios_debug\", \"targets\": []}}, \"config_name\": \"config_name\", \"environment\": \"Staging\", \"recipe\": \"engine_v2/builder\"}, \"requestId\": \"8945511751514863184-00000000-0000-0000-0000-000000001337\", \"swarming\": {\"parentRunId\": \"fake-task-id\"}, \"tags\": [{\"key\": \"cq_experimental\", \"value\": \"false\"}, {\"key\": \"parent_buildbucket_id\", \"value\": \"8945511751514863184\"}, {\"key\": \"user_agent\", \"value\": \"recipe\"}]}}]}",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -301,15 +312,15 @@
       "@@@STEP_LOG_LINE@request@        \"gerritChanges\": [@@@",
       "@@@STEP_LOG_LINE@request@          {@@@",
       "@@@STEP_LOG_LINE@request@            \"change\": \"123456\", @@@",
-      "@@@STEP_LOG_LINE@request@            \"host\": \"github.com\", @@@",
+      "@@@STEP_LOG_LINE@request@            \"host\": \"flutter-review.googlesource.com\", @@@",
       "@@@STEP_LOG_LINE@request@            \"patchset\": \"7\", @@@",
-      "@@@STEP_LOG_LINE@request@            \"project\": \"repo/a\"@@@",
+      "@@@STEP_LOG_LINE@request@            \"project\": \"mirrors/engine\"@@@",
       "@@@STEP_LOG_LINE@request@          }@@@",
       "@@@STEP_LOG_LINE@request@        ], @@@",
       "@@@STEP_LOG_LINE@request@        \"gitilesCommit\": {@@@",
-      "@@@STEP_LOG_LINE@request@          \"host\": \"github.com\", @@@",
+      "@@@STEP_LOG_LINE@request@          \"host\": \"flutter.googlesource.com\", @@@",
       "@@@STEP_LOG_LINE@request@          \"id\": \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\", @@@",
-      "@@@STEP_LOG_LINE@request@          \"project\": \"repo/a\", @@@",
+      "@@@STEP_LOG_LINE@request@          \"project\": \"mirrors/engine\", @@@",
       "@@@STEP_LOG_LINE@request@          \"ref\": \"refs/heads/main\"@@@",
       "@@@STEP_LOG_LINE@request@        }, @@@",
       "@@@STEP_LOG_LINE@request@        \"priority\": 25, @@@",
@@ -330,6 +341,7 @@
       "@@@STEP_LOG_LINE@request@              \"targets\": []@@@",
       "@@@STEP_LOG_LINE@request@            }@@@",
       "@@@STEP_LOG_LINE@request@          }, @@@",
+      "@@@STEP_LOG_LINE@request@          \"config_name\": \"config_name\", @@@",
       "@@@STEP_LOG_LINE@request@          \"environment\": \"Staging\", @@@",
       "@@@STEP_LOG_LINE@request@          \"recipe\": \"engine_v2/builder\"@@@",
       "@@@STEP_LOG_LINE@request@        }, @@@",
@@ -498,51 +510,6 @@
     ]
   },
   {
-    "cmd": [
-      "python3",
-      "-u",
-      "RECIPE_MODULE[recipe_engine::json]/resources/read.py",
-      "[START_DIR]/engine/ci/builders/None.json",
-      "/path/to/tmp/json"
-    ],
-    "luci_context": {
-      "realm": {
-        "name": "proj:try"
-      },
-      "resultdb": {
-        "current_invocation": {
-          "name": "invocations/build:8945511751514863184",
-          "update_token": "token"
-        },
-        "hostname": "rdbhost"
-      }
-    },
-    "name": "Read build config file (2)",
-    "~followup_annotations": [
-      "@@@STEP_LOG_LINE@json.output@{@@@",
-      "@@@STEP_LOG_LINE@json.output@  \"builds\": [@@@",
-      "@@@STEP_LOG_LINE@json.output@    {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"generators\": [@@@",
-      "@@@STEP_LOG_LINE@json.output@        {@@@",
-      "@@@STEP_LOG_LINE@json.output@          \"name\": \"generator1\", @@@",
-      "@@@STEP_LOG_LINE@json.output@          \"script\": \"script1.sh\"@@@",
-      "@@@STEP_LOG_LINE@json.output@        }@@@",
-      "@@@STEP_LOG_LINE@json.output@      ], @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"gn\": [@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"--ios\"@@@",
-      "@@@STEP_LOG_LINE@json.output@      ], @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"name\": \"ios_debug\", @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"ninja\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"config\": \"ios_debug\", @@@",
-      "@@@STEP_LOG_LINE@json.output@        \"targets\": []@@@",
-      "@@@STEP_LOG_LINE@json.output@      }@@@",
-      "@@@STEP_LOG_LINE@json.output@    }@@@",
-      "@@@STEP_LOG_LINE@json.output@  ]@@@",
-      "@@@STEP_LOG_LINE@json.output@}@@@",
-      "@@@STEP_LOG_END@json.output@@@"
-    ]
-  },
-  {
     "cmd": [],
     "name": "launch tests"
   },
@@ -556,12 +523,17 @@
   },
   {
     "cmd": [
-      "python3",
+      "vpython3",
       "-u",
-      "RECIPE_MODULE[recipe_engine::json]/resources/read.py",
-      "[START_DIR]/engine/ci/builders/None.json",
-      "/path/to/tmp/json"
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "ensure-directory",
+      "--mode",
+      "0777",
+      "[CACHE]/builder"
     ],
+    "infra_step": true,
     "luci_context": {
       "realm": {
         "name": "proj:try"
@@ -574,20 +546,259 @@
         "hostname": "rdbhost"
       }
     },
-    "name": "Read build config file (3)",
+    "name": "Ensure full engine checkout folder"
+  },
+  {
+    "cmd": [],
+    "name": "Checkout source code"
+  },
+  {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "rmcontents",
+      "[CACHE]/builder"
+    ],
+    "env_suffixes": {
+      "DEPOT_TOOLS_UPDATE": [
+        "0"
+      ],
+      "PATH": [
+        "RECIPE_REPO[depot_tools]"
+      ]
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "Checkout source code.Clobber cache",
     "~followup_annotations": [
-      "@@@STEP_LOG_LINE@json.output@{}@@@",
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "rmtree",
+      "[CACHE]/git"
+    ],
+    "env_suffixes": {
+      "DEPOT_TOOLS_UPDATE": [
+        "0"
+      ],
+      "PATH": [
+        "RECIPE_REPO[depot_tools]"
+      ]
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "Checkout source code.Clobber git cache",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "ensure-directory",
+      "--mode",
+      "0777",
+      "[CACHE]/builder"
+    ],
+    "env_suffixes": {
+      "DEPOT_TOOLS_UPDATE": [
+        "0"
+      ],
+      "PATH": [
+        "RECIPE_REPO[depot_tools]"
+      ]
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "Checkout source code.Ensure checkout cache",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "vpython3",
+      "RECIPE_REPO[depot_tools]/gerrit_client.py",
+      "changes",
+      "--host",
+      "https://flutter-review.googlesource.com",
+      "--json_file",
+      "/path/to/tmp/json",
+      "--limit",
+      "1",
+      "-p",
+      "change=123456",
+      "-o",
+      "ALL_REVISIONS",
+      "-o",
+      "DOWNLOAD_COMMANDS"
+    ],
+    "cwd": "[CACHE]/builder",
+    "env": {
+      "ANDROID_HOME": "[CACHE]/builder/third_party/android_tools/sdk",
+      "DEPOT_TOOLS": "RECIPE_REPO[depot_tools]",
+      "ENGINE_CHECKOUT_PATH": "[CACHE]/builder",
+      "GIT_BRANCH": "",
+      "LUCI_BRANCH": "",
+      "LUCI_CI": "True",
+      "LUCI_PR": "",
+      "LUCI_WORKDIR": "[START_DIR]",
+      "OS": "linux",
+      "PATH": "<PATH>:RECIPE_REPO[depot_tools]",
+      "REVISION": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    },
+    "env_prefixes": {
+      "PATH": [
+        "[CACHE]/builder/third_party/dart/tools/sdks/dart-sdk/bin"
+      ]
+    },
+    "env_suffixes": {
+      "DEPOT_TOOLS_UPDATE": [
+        "0"
+      ],
+      "PATH": [
+        "RECIPE_REPO[depot_tools]"
+      ]
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "Checkout source code.gerrit fetch current CL info",
+    "timeout": 60,
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_LOG_LINE@json.output@[@@@",
+      "@@@STEP_LOG_LINE@json.output@  {@@@",
+      "@@@STEP_LOG_LINE@json.output@    \"branch\": \"main\", @@@",
+      "@@@STEP_LOG_LINE@json.output@    \"owner\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"name\": \"John Doe\"@@@",
+      "@@@STEP_LOG_LINE@json.output@    }, @@@",
+      "@@@STEP_LOG_LINE@json.output@    \"revisions\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"184ebe53805e102605d11f6b143486d15c23a09c\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@        \"_number\": \"7\", @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"ref\": \"refs/changes/56/123456/7\"@@@",
+      "@@@STEP_LOG_LINE@json.output@      }@@@",
+      "@@@STEP_LOG_LINE@json.output@    }@@@",
+      "@@@STEP_LOG_LINE@json.output@  }@@@",
+      "@@@STEP_LOG_LINE@json.output@]@@@",
       "@@@STEP_LOG_END@json.output@@@"
     ]
   },
   {
     "cmd": [
-      "python3",
+      "vpython3",
       "-u",
-      "RECIPE_MODULE[recipe_engine::json]/resources/read.py",
-      "[START_DIR]/engine/ci/builders/None.json",
-      "/path/to/tmp/json"
+      "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
+      "--spec-path",
+      "cache_dir = '[CACHE]/git'\nsolutions = [{'deps_file': '.DEPS.git', 'managed': False, 'name': 'src/flutter', 'url': 'https://flutter.googlesource.com/mirrors/engine'}]",
+      "--patch_root",
+      "src/flutter",
+      "--revision_mapping_file",
+      "{\"got_engine_revision\": \"src/flutter\"}",
+      "--git-cache-dir",
+      "[CACHE]/git",
+      "--cleanup-dir",
+      "[CLEANUP]/bot_update",
+      "--output_json",
+      "/path/to/tmp/json",
+      "--patch_ref",
+      "https://flutter.googlesource.com/mirrors/engine@refs/heads/main:refs/changes/56/123456/7",
+      "--revision",
+      "src/flutter@refs/heads/main",
+      "--refs",
+      "refs/heads/main",
+      "--refs",
+      "refs/heads/main"
     ],
+    "cwd": "[CACHE]/builder",
+    "env": {
+      "ANDROID_HOME": "[CACHE]/builder/third_party/android_tools/sdk",
+      "DEPOT_TOOLS": "RECIPE_REPO[depot_tools]",
+      "DEPOT_TOOLS_REPORT_BUILD": "proj/try/try-builder/8945511751514863184",
+      "ENGINE_CHECKOUT_PATH": "[CACHE]/builder",
+      "GIT_BRANCH": "",
+      "GIT_HTTP_LOW_SPEED_LIMIT": "102400",
+      "GIT_HTTP_LOW_SPEED_TIME": "1800",
+      "LUCI_BRANCH": "",
+      "LUCI_CI": "True",
+      "LUCI_PR": "",
+      "LUCI_WORKDIR": "[START_DIR]",
+      "OS": "linux",
+      "REVISION": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    },
+    "env_prefixes": {
+      "PATH": [
+        "[CACHE]/builder/third_party/dart/tools/sdks/dart-sdk/bin"
+      ]
+    },
+    "env_suffixes": {
+      "DEPOT_TOOLS_UPDATE": [
+        "0",
+        "0"
+      ],
+      "PATH": [
+        "RECIPE_REPO[depot_tools]",
+        "RECIPE_REPO[depot_tools]"
+      ]
+    },
+    "infra_step": true,
     "luci_context": {
       "realm": {
         "name": "proj:try"
@@ -600,10 +811,151 @@
         "hostname": "rdbhost"
       }
     },
-    "name": "Read build config file (4)",
+    "name": "Checkout source code.bot_update",
     "~followup_annotations": [
-      "@@@STEP_LOG_LINE@json.output@{}@@@",
-      "@@@STEP_LOG_END@json.output@@@"
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_TEXT@Some step text@@@",
+      "@@@STEP_LOG_LINE@json.output@{@@@",
+      "@@@STEP_LOG_LINE@json.output@  \"did_run\": true, @@@",
+      "@@@STEP_LOG_LINE@json.output@  \"fixed_revisions\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@    \"src/flutter\": \"refs/heads/main\"@@@",
+      "@@@STEP_LOG_LINE@json.output@  }, @@@",
+      "@@@STEP_LOG_LINE@json.output@  \"manifest\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@    \"src/flutter\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"repository\": \"https://fake.org/src/flutter.git\", @@@",
+      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"e1f32bac24d72ebe0a5713009ae850c6320e7c7d\"@@@",
+      "@@@STEP_LOG_LINE@json.output@    }@@@",
+      "@@@STEP_LOG_LINE@json.output@  }, @@@",
+      "@@@STEP_LOG_LINE@json.output@  \"patch_failure\": false, @@@",
+      "@@@STEP_LOG_LINE@json.output@  \"patch_root\": \"src/flutter\", @@@",
+      "@@@STEP_LOG_LINE@json.output@  \"properties\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@    \"got_engine_revision\": \"e1f32bac24d72ebe0a5713009ae850c6320e7c7d\", @@@",
+      "@@@STEP_LOG_LINE@json.output@    \"got_engine_revision_cp\": \"refs/heads/main@{#84512}\", @@@",
+      "@@@STEP_LOG_LINE@json.output@    \"got_revision\": \"9221bca00ddbd888260084def81f09543281b952\"@@@",
+      "@@@STEP_LOG_LINE@json.output@  }, @@@",
+      "@@@STEP_LOG_LINE@json.output@  \"root\": \"src/flutter\", @@@",
+      "@@@STEP_LOG_LINE@json.output@  \"source_manifest\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@    \"directories\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"src/flutter\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@        \"git_checkout\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@          \"repo_url\": \"https://fake.org/src/flutter.git\", @@@",
+      "@@@STEP_LOG_LINE@json.output@          \"revision\": \"e1f32bac24d72ebe0a5713009ae850c6320e7c7d\"@@@",
+      "@@@STEP_LOG_LINE@json.output@        }@@@",
+      "@@@STEP_LOG_LINE@json.output@      }@@@",
+      "@@@STEP_LOG_LINE@json.output@    }, @@@",
+      "@@@STEP_LOG_LINE@json.output@    \"version\": 0@@@",
+      "@@@STEP_LOG_LINE@json.output@  }, @@@",
+      "@@@STEP_LOG_LINE@json.output@  \"step_text\": \"Some step text\"@@@",
+      "@@@STEP_LOG_LINE@json.output@}@@@",
+      "@@@STEP_LOG_END@json.output@@@",
+      "@@@SET_BUILD_PROPERTY@got_engine_revision@\"e1f32bac24d72ebe0a5713009ae850c6320e7c7d\"@@@",
+      "@@@SET_BUILD_PROPERTY@got_engine_revision_cp@\"refs/heads/main@{#84512}\"@@@",
+      "@@@SET_BUILD_PROPERTY@got_revision@\"9221bca00ddbd888260084def81f09543281b952\"@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_REPO[depot_tools]/gclient.py",
+      "runhooks"
+    ],
+    "cwd": "[CACHE]/builder",
+    "env": {
+      "ANDROID_HOME": "[CACHE]/builder/third_party/android_tools/sdk",
+      "DEPOT_TOOLS": "RECIPE_REPO[depot_tools]",
+      "DEPOT_TOOLS_REPORT_BUILD": "proj/try/try-builder/8945511751514863184",
+      "ENGINE_CHECKOUT_PATH": "[CACHE]/builder",
+      "GIT_BRANCH": "",
+      "LUCI_BRANCH": "",
+      "LUCI_CI": "True",
+      "LUCI_PR": "",
+      "LUCI_WORKDIR": "[START_DIR]",
+      "OS": "linux",
+      "REVISION": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    },
+    "env_prefixes": {
+      "PATH": [
+        "[CACHE]/builder/third_party/dart/tools/sdks/dart-sdk/bin"
+      ]
+    },
+    "env_suffixes": {
+      "DEPOT_TOOLS_UPDATE": [
+        "0"
+      ],
+      "PATH": [
+        "RECIPE_REPO[depot_tools]",
+        "RECIPE_REPO[depot_tools]"
+      ]
+    },
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "Checkout source code.gclient runhooks",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "git",
+      "rev-parse",
+      "HEAD"
+    ],
+    "cwd": "[CACHE]/builder/src/flutter",
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "git rev-parse"
+  },
+  {
+    "cmd": [
+      "python3",
+      "-u",
+      "RECIPE_MODULE[depot_tools::gsutil]/resources/gsutil_smart_retry.py",
+      "--",
+      "RECIPE_REPO[depot_tools]/gsutil.py",
+      "----",
+      "cp",
+      "-r",
+      "/a/b/c.txt",
+      "gs://flutter_archives_v2/flutter_infra_release/flutter//bucket/c.txt"
+    ],
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "gsutil c.txt",
+    "~followup_annotations": [
+      "@@@STEP_LINK@gsutil.upload@https://console.cloud.google.com/storage/browser/flutter_archives_v2/flutter_infra_release/flutter//bucket/c.txt@@@"
     ]
   },
   {
diff --git a/recipes/engine_v2/engine_v2.expected/monorepo_linux.json b/recipes/engine_v2/engine_v2.expected/monorepo_linux.json
new file mode 100644
index 0000000..e0b4097
--- /dev/null
+++ b/recipes/engine_v2/engine_v2.expected/monorepo_linux.json
@@ -0,0 +1,294 @@
+[
+  {
+    "cmd": [],
+    "name": "launch builds"
+  },
+  {
+    "cmd": [
+      "bb",
+      "batch",
+      "-host",
+      "cr-buildbucket.appspot.com"
+    ],
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "launch builds.schedule",
+    "stdin": "{\"requests\": [{\"scheduleBuild\": {\"builder\": {\"bucket\": \"try\", \"builder\": \"Linux Staging Engine Drone\", \"project\": \"proj\"}, \"exe\": {\"cipdVersion\": \"refs/heads/main\"}, \"experimental\": \"NO\", \"experiments\": {\"luci.buildbucket.parent_tracking\": false}, \"fields\": \"builder,createTime,createdBy,critical,endTime,id,infra,input,number,output,startTime,status,updateTime\", \"gerritChanges\": [{\"change\": \"123456\", \"host\": \"dart-review.googlesource.com\", \"patchset\": \"7\", \"project\": \"monorepo\"}], \"gitilesCommit\": {\"host\": \"dart.googlesource.com\", \"id\": \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\", \"project\": \"monorepo\", \"ref\": \"refs/heads/main\"}, \"priority\": 25, \"properties\": {\"build\": {\"generators\": [{\"name\": \"generator1\", \"script\": \"script1.sh\"}], \"gn\": [\"--ios\"], \"name\": \"ios_debug\", \"ninja\": {\"config\": \"ios_debug\", \"targets\": []}}, \"builds\": [{\"generators\": [{\"name\": \"generator1\", \"script\": \"script1.sh\"}], \"gn\": [\"--ios\"], \"name\": \"ios_debug\", \"ninja\": {\"config\": \"ios_debug\", \"targets\": []}}], \"environment\": \"Staging\", \"recipe\": \"engine_v2/builder\"}, \"requestId\": \"8945511751514863184-00000000-0000-0000-0000-000000001337\", \"swarming\": {\"parentRunId\": \"fake-task-id\"}, \"tags\": [{\"key\": \"cq_experimental\", \"value\": \"false\"}, {\"key\": \"parent_buildbucket_id\", \"value\": \"8945511751514863184\"}, {\"key\": \"user_agent\", \"value\": \"recipe\"}]}}]}",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_LOG_LINE@json.output@{@@@",
+      "@@@STEP_LOG_LINE@json.output@  \"responses\": [@@@",
+      "@@@STEP_LOG_LINE@json.output@    {@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"scheduleBuild\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@        \"builder\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@          \"bucket\": \"try\", @@@",
+      "@@@STEP_LOG_LINE@json.output@          \"builder\": \"builder-subbuild1\", @@@",
+      "@@@STEP_LOG_LINE@json.output@          \"project\": \"fuchsia\"@@@",
+      "@@@STEP_LOG_LINE@json.output@        }, @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"id\": \"8945511751514863186\"@@@",
+      "@@@STEP_LOG_LINE@json.output@      }@@@",
+      "@@@STEP_LOG_LINE@json.output@    }@@@",
+      "@@@STEP_LOG_LINE@json.output@  ]@@@",
+      "@@@STEP_LOG_LINE@json.output@}@@@",
+      "@@@STEP_LOG_END@json.output@@@",
+      "@@@STEP_LOG_LINE@request@{@@@",
+      "@@@STEP_LOG_LINE@request@  \"requests\": [@@@",
+      "@@@STEP_LOG_LINE@request@    {@@@",
+      "@@@STEP_LOG_LINE@request@      \"scheduleBuild\": {@@@",
+      "@@@STEP_LOG_LINE@request@        \"builder\": {@@@",
+      "@@@STEP_LOG_LINE@request@          \"bucket\": \"try\", @@@",
+      "@@@STEP_LOG_LINE@request@          \"builder\": \"Linux Staging Engine Drone\", @@@",
+      "@@@STEP_LOG_LINE@request@          \"project\": \"proj\"@@@",
+      "@@@STEP_LOG_LINE@request@        }, @@@",
+      "@@@STEP_LOG_LINE@request@        \"exe\": {@@@",
+      "@@@STEP_LOG_LINE@request@          \"cipdVersion\": \"refs/heads/main\"@@@",
+      "@@@STEP_LOG_LINE@request@        }, @@@",
+      "@@@STEP_LOG_LINE@request@        \"experimental\": \"NO\", @@@",
+      "@@@STEP_LOG_LINE@request@        \"experiments\": {@@@",
+      "@@@STEP_LOG_LINE@request@          \"luci.buildbucket.parent_tracking\": false@@@",
+      "@@@STEP_LOG_LINE@request@        }, @@@",
+      "@@@STEP_LOG_LINE@request@        \"fields\": \"builder,createTime,createdBy,critical,endTime,id,infra,input,number,output,startTime,status,updateTime\", @@@",
+      "@@@STEP_LOG_LINE@request@        \"gerritChanges\": [@@@",
+      "@@@STEP_LOG_LINE@request@          {@@@",
+      "@@@STEP_LOG_LINE@request@            \"change\": \"123456\", @@@",
+      "@@@STEP_LOG_LINE@request@            \"host\": \"dart-review.googlesource.com\", @@@",
+      "@@@STEP_LOG_LINE@request@            \"patchset\": \"7\", @@@",
+      "@@@STEP_LOG_LINE@request@            \"project\": \"monorepo\"@@@",
+      "@@@STEP_LOG_LINE@request@          }@@@",
+      "@@@STEP_LOG_LINE@request@        ], @@@",
+      "@@@STEP_LOG_LINE@request@        \"gitilesCommit\": {@@@",
+      "@@@STEP_LOG_LINE@request@          \"host\": \"dart.googlesource.com\", @@@",
+      "@@@STEP_LOG_LINE@request@          \"id\": \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\", @@@",
+      "@@@STEP_LOG_LINE@request@          \"project\": \"monorepo\", @@@",
+      "@@@STEP_LOG_LINE@request@          \"ref\": \"refs/heads/main\"@@@",
+      "@@@STEP_LOG_LINE@request@        }, @@@",
+      "@@@STEP_LOG_LINE@request@        \"priority\": 25, @@@",
+      "@@@STEP_LOG_LINE@request@        \"properties\": {@@@",
+      "@@@STEP_LOG_LINE@request@          \"build\": {@@@",
+      "@@@STEP_LOG_LINE@request@            \"generators\": [@@@",
+      "@@@STEP_LOG_LINE@request@              {@@@",
+      "@@@STEP_LOG_LINE@request@                \"name\": \"generator1\", @@@",
+      "@@@STEP_LOG_LINE@request@                \"script\": \"script1.sh\"@@@",
+      "@@@STEP_LOG_LINE@request@              }@@@",
+      "@@@STEP_LOG_LINE@request@            ], @@@",
+      "@@@STEP_LOG_LINE@request@            \"gn\": [@@@",
+      "@@@STEP_LOG_LINE@request@              \"--ios\"@@@",
+      "@@@STEP_LOG_LINE@request@            ], @@@",
+      "@@@STEP_LOG_LINE@request@            \"name\": \"ios_debug\", @@@",
+      "@@@STEP_LOG_LINE@request@            \"ninja\": {@@@",
+      "@@@STEP_LOG_LINE@request@              \"config\": \"ios_debug\", @@@",
+      "@@@STEP_LOG_LINE@request@              \"targets\": []@@@",
+      "@@@STEP_LOG_LINE@request@            }@@@",
+      "@@@STEP_LOG_LINE@request@          }, @@@",
+      "@@@STEP_LOG_LINE@request@          \"builds\": [@@@",
+      "@@@STEP_LOG_LINE@request@            {@@@",
+      "@@@STEP_LOG_LINE@request@              \"generators\": [@@@",
+      "@@@STEP_LOG_LINE@request@                {@@@",
+      "@@@STEP_LOG_LINE@request@                  \"name\": \"generator1\", @@@",
+      "@@@STEP_LOG_LINE@request@                  \"script\": \"script1.sh\"@@@",
+      "@@@STEP_LOG_LINE@request@                }@@@",
+      "@@@STEP_LOG_LINE@request@              ], @@@",
+      "@@@STEP_LOG_LINE@request@              \"gn\": [@@@",
+      "@@@STEP_LOG_LINE@request@                \"--ios\"@@@",
+      "@@@STEP_LOG_LINE@request@              ], @@@",
+      "@@@STEP_LOG_LINE@request@              \"name\": \"ios_debug\", @@@",
+      "@@@STEP_LOG_LINE@request@              \"ninja\": {@@@",
+      "@@@STEP_LOG_LINE@request@                \"config\": \"ios_debug\", @@@",
+      "@@@STEP_LOG_LINE@request@                \"targets\": []@@@",
+      "@@@STEP_LOG_LINE@request@              }@@@",
+      "@@@STEP_LOG_LINE@request@            }@@@",
+      "@@@STEP_LOG_LINE@request@          ], @@@",
+      "@@@STEP_LOG_LINE@request@          \"environment\": \"Staging\", @@@",
+      "@@@STEP_LOG_LINE@request@          \"recipe\": \"engine_v2/builder\"@@@",
+      "@@@STEP_LOG_LINE@request@        }, @@@",
+      "@@@STEP_LOG_LINE@request@        \"requestId\": \"8945511751514863184-00000000-0000-0000-0000-000000001337\", @@@",
+      "@@@STEP_LOG_LINE@request@        \"swarming\": {@@@",
+      "@@@STEP_LOG_LINE@request@          \"parentRunId\": \"fake-task-id\"@@@",
+      "@@@STEP_LOG_LINE@request@        }, @@@",
+      "@@@STEP_LOG_LINE@request@        \"tags\": [@@@",
+      "@@@STEP_LOG_LINE@request@          {@@@",
+      "@@@STEP_LOG_LINE@request@            \"key\": \"cq_experimental\", @@@",
+      "@@@STEP_LOG_LINE@request@            \"value\": \"false\"@@@",
+      "@@@STEP_LOG_LINE@request@          }, @@@",
+      "@@@STEP_LOG_LINE@request@          {@@@",
+      "@@@STEP_LOG_LINE@request@            \"key\": \"parent_buildbucket_id\", @@@",
+      "@@@STEP_LOG_LINE@request@            \"value\": \"8945511751514863184\"@@@",
+      "@@@STEP_LOG_LINE@request@          }, @@@",
+      "@@@STEP_LOG_LINE@request@          {@@@",
+      "@@@STEP_LOG_LINE@request@            \"key\": \"user_agent\", @@@",
+      "@@@STEP_LOG_LINE@request@            \"value\": \"recipe\"@@@",
+      "@@@STEP_LOG_LINE@request@          }@@@",
+      "@@@STEP_LOG_LINE@request@        ]@@@",
+      "@@@STEP_LOG_LINE@request@      }@@@",
+      "@@@STEP_LOG_LINE@request@    }@@@",
+      "@@@STEP_LOG_LINE@request@  ]@@@",
+      "@@@STEP_LOG_LINE@request@}@@@",
+      "@@@STEP_LOG_END@request@@@",
+      "@@@STEP_LINK@8945511751514863186@https://cr-buildbucket.appspot.com/build/8945511751514863186@@@"
+    ]
+  },
+  {
+    "cmd": [],
+    "name": "collect builds"
+  },
+  {
+    "cmd": [],
+    "name": "collect builds.collect",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "bb",
+      "collect",
+      "-host",
+      "cr-buildbucket.appspot.com",
+      "-interval",
+      "20s",
+      "8945511751514863186"
+    ],
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "collect builds.collect.wait",
+    "timeout": 86400,
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@2@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "bb",
+      "batch",
+      "-host",
+      "cr-buildbucket.appspot.com"
+    ],
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "collect builds.collect.get",
+    "stdin": "{\"requests\": [{\"getBuild\": {\"fields\": \"builder,createTime,createdBy,critical,endTime,id,infra,infra.swarming.taskId,input,number,output,startTime,status,summaryMarkdown,updateTime\", \"id\": \"8945511751514863186\"}}]}",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@2@@@",
+      "@@@STEP_LOG_LINE@json.output@{@@@",
+      "@@@STEP_LOG_LINE@json.output@  \"responses\": [@@@",
+      "@@@STEP_LOG_LINE@json.output@    {@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"getBuild\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@        \"builder\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@          \"bucket\": \"try\", @@@",
+      "@@@STEP_LOG_LINE@json.output@          \"builder\": \"builder-subbuild1\", @@@",
+      "@@@STEP_LOG_LINE@json.output@          \"project\": \"fuchsia\"@@@",
+      "@@@STEP_LOG_LINE@json.output@        }, @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"createTime\": \"2018-05-25T23:50:17Z\", @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"createdBy\": \"project:fuchsia\", @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"id\": \"8945511751514863186\", @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"infra\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@          \"resultdb\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@            \"invocation\": \"invocations/build:8945511751514863186\"@@@",
+      "@@@STEP_LOG_LINE@json.output@          }, @@@",
+      "@@@STEP_LOG_LINE@json.output@          \"swarming\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@            \"priority\": 30, @@@",
+      "@@@STEP_LOG_LINE@json.output@            \"taskId\": \"abc123\"@@@",
+      "@@@STEP_LOG_LINE@json.output@          }@@@",
+      "@@@STEP_LOG_LINE@json.output@        }, @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"input\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@          \"gerritChanges\": [@@@",
+      "@@@STEP_LOG_LINE@json.output@            {@@@",
+      "@@@STEP_LOG_LINE@json.output@              \"change\": \"123456\", @@@",
+      "@@@STEP_LOG_LINE@json.output@              \"host\": \"chromium-review.googlesource.com\", @@@",
+      "@@@STEP_LOG_LINE@json.output@              \"patchset\": \"7\", @@@",
+      "@@@STEP_LOG_LINE@json.output@              \"project\": \"fuchsia\"@@@",
+      "@@@STEP_LOG_LINE@json.output@            }@@@",
+      "@@@STEP_LOG_LINE@json.output@          ]@@@",
+      "@@@STEP_LOG_LINE@json.output@        }, @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"output\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@          \"properties\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@            \"test_orchestration_inputs_hash\": \"abc\"@@@",
+      "@@@STEP_LOG_LINE@json.output@          }@@@",
+      "@@@STEP_LOG_LINE@json.output@        }, @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"status\": \"SUCCESS\", @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"tags\": [@@@",
+      "@@@STEP_LOG_LINE@json.output@          {@@@",
+      "@@@STEP_LOG_LINE@json.output@            \"key\": \"cq_experimental\", @@@",
+      "@@@STEP_LOG_LINE@json.output@            \"value\": \"false\"@@@",
+      "@@@STEP_LOG_LINE@json.output@          }@@@",
+      "@@@STEP_LOG_LINE@json.output@        ]@@@",
+      "@@@STEP_LOG_LINE@json.output@      }@@@",
+      "@@@STEP_LOG_LINE@json.output@    }@@@",
+      "@@@STEP_LOG_LINE@json.output@  ]@@@",
+      "@@@STEP_LOG_LINE@json.output@}@@@",
+      "@@@STEP_LOG_END@json.output@@@",
+      "@@@STEP_LOG_LINE@request@{@@@",
+      "@@@STEP_LOG_LINE@request@  \"requests\": [@@@",
+      "@@@STEP_LOG_LINE@request@    {@@@",
+      "@@@STEP_LOG_LINE@request@      \"getBuild\": {@@@",
+      "@@@STEP_LOG_LINE@request@        \"fields\": \"builder,createTime,createdBy,critical,endTime,id,infra,infra.swarming.taskId,input,number,output,startTime,status,summaryMarkdown,updateTime\", @@@",
+      "@@@STEP_LOG_LINE@request@        \"id\": \"8945511751514863186\"@@@",
+      "@@@STEP_LOG_LINE@request@      }@@@",
+      "@@@STEP_LOG_LINE@request@    }@@@",
+      "@@@STEP_LOG_LINE@request@  ]@@@",
+      "@@@STEP_LOG_LINE@request@}@@@",
+      "@@@STEP_LOG_END@request@@@",
+      "@@@STEP_LINK@8945511751514863186@https://cr-buildbucket.appspot.com/build/8945511751514863186@@@"
+    ]
+  },
+  {
+    "cmd": [],
+    "name": "display builds"
+  },
+  {
+    "cmd": [],
+    "name": "display builds.builder-subbuild1",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_LINK@8945511751514863186@https://cr-buildbucket.appspot.com/build/8945511751514863186@@@"
+    ]
+  },
+  {
+    "cmd": [],
+    "name": "launch tests"
+  },
+  {
+    "cmd": [],
+    "name": "collect tests"
+  },
+  {
+    "cmd": [],
+    "name": "display tests"
+  },
+  {
+    "name": "$result"
+  }
+]
\ No newline at end of file
diff --git a/recipes/engine_v2/engine_v2.expected/overridden_config_from_file.json b/recipes/engine_v2/engine_v2.expected/overridden_config_from_file.json
new file mode 100644
index 0000000..f0e4a78
--- /dev/null
+++ b/recipes/engine_v2/engine_v2.expected/overridden_config_from_file.json
@@ -0,0 +1,261 @@
+[
+  {
+    "cmd": [],
+    "name": "Checkout flutter/engine"
+  },
+  {
+    "cmd": [
+      "python3",
+      "-u",
+      "RECIPE_MODULE[depot_tools::git]/resources/git_setup.py",
+      "--path",
+      "[START_DIR]/engine",
+      "--url",
+      "https://flutter.googlesource.com/mirrors/engine"
+    ],
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "Checkout flutter/engine.git setup",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "git",
+      "fetch",
+      "origin",
+      "--recurse-submodules",
+      "--progress",
+      "--tags"
+    ],
+    "cwd": "[START_DIR]/engine",
+    "env": {
+      "PATH": "RECIPE_REPO[depot_tools]:<PATH>"
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "Checkout flutter/engine.git fetch",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "git",
+      "checkout",
+      "-f",
+      "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+    ],
+    "cwd": "[START_DIR]/engine",
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "Checkout flutter/engine.git checkout",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "git",
+      "rev-parse",
+      "HEAD"
+    ],
+    "cwd": "[START_DIR]/engine",
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "Checkout flutter/engine.read revision",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_TEXT@<br/>checked out 'deadbeef'<br/>@@@",
+      "@@@SET_BUILD_PROPERTY@got_revision@\"deadbeef\"@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "git",
+      "clean",
+      "-f",
+      "-d",
+      "-x"
+    ],
+    "cwd": "[START_DIR]/engine",
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "Checkout flutter/engine.git clean",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "git",
+      "submodule",
+      "sync"
+    ],
+    "cwd": "[START_DIR]/engine",
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "Checkout flutter/engine.submodule sync",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "git",
+      "submodule",
+      "update",
+      "--init",
+      "--recursive"
+    ],
+    "cwd": "[START_DIR]/engine",
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "Checkout flutter/engine.submodule update",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "copy",
+      "[START_DIR]/engine/ci/builders/overridden_config_name.json",
+      "/path/to/tmp/"
+    ],
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "proj:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "Read build config file",
+    "~followup_annotations": [
+      "@@@STEP_LOG_LINE@overridden_config_name.json@{@@@",
+      "@@@STEP_LOG_LINE@overridden_config_name.json@  \"archives\": [@@@",
+      "@@@STEP_LOG_LINE@overridden_config_name.json@    {@@@",
+      "@@@STEP_LOG_LINE@overridden_config_name.json@      \"destination\": \"bucket/c.txt\",@@@",
+      "@@@STEP_LOG_LINE@overridden_config_name.json@      \"name\": \"c.txt\",@@@",
+      "@@@STEP_LOG_LINE@overridden_config_name.json@      \"source\": \"/a/b/c.txt\"@@@",
+      "@@@STEP_LOG_LINE@overridden_config_name.json@    }@@@",
+      "@@@STEP_LOG_LINE@overridden_config_name.json@  ]@@@",
+      "@@@STEP_LOG_LINE@overridden_config_name.json@}@@@",
+      "@@@STEP_LOG_END@overridden_config_name.json@@@"
+    ]
+  },
+  {
+    "cmd": [],
+    "name": "launch builds"
+  },
+  {
+    "cmd": [],
+    "name": "collect builds"
+  },
+  {
+    "cmd": [],
+    "name": "display builds"
+  },
+  {
+    "cmd": [],
+    "name": "launch tests"
+  },
+  {
+    "cmd": [],
+    "name": "collect tests"
+  },
+  {
+    "cmd": [],
+    "name": "display tests"
+  },
+  {
+    "name": "$result"
+  }
+]
\ No newline at end of file
diff --git a/recipes/engine_v2/engine_v2.py b/recipes/engine_v2/engine_v2.py
index 63fa534..0afce92 100644
--- a/recipes/engine_v2/engine_v2.py
+++ b/recipes/engine_v2/engine_v2.py
@@ -45,24 +45,41 @@
 
 def RunSteps(api, properties, env_properties):
   config_name = api.properties.get('config_name')
-  # Checkout engine repository only.
-  checkout_path = api.path['start_dir'].join('engine')
-  api.repo_util.checkout(
-      'engine',
-      checkout_path=checkout_path,
-      url=api.properties.get('git_url'),
-      ref=api.properties.get('git_ref')
-  )
-
-  # Read builds configuration from repository under test.
-  config_path = checkout_path.join('ci', 'builders', '%s.json' % config_name)
   builds = api.properties.get('builds')
+  tests = api.properties.get('tests')
+  generators = api.properties.get('generators')
+  archives = api.properties.get('archives')
+  if config_name:
+    # Read builds configuration from repository under test.
+    # Checkout engine repository only.
+    checkout_path = api.path['start_dir'].join('engine')
+    api.repo_util.checkout(
+        'engine',
+        checkout_path=checkout_path,
+        url=api.properties.get('git_url'),
+        ref=api.properties.get('git_ref')
+    )
+    config_path = checkout_path.join('ci', 'builders', '%s.json' % config_name)
+    config = api.file.read_json(
+        'Read build config file', config_path, test_data={}
+    )
+    if builds is None:
+      builds = config.get('builds')
+    if tests is None:
+      tests = config.get('tests')
+    if generators is None:
+      generators = config.get('generators')
+    if archives is None:
+      archives = config.get('archives')
   if builds is None:
-    builds = api.json.read(
-        'Read build config file',
-        config_path,
-        step_test_data=lambda: api.json.test_api.output({})
-    ).json.output.get('builds', [])
+    builds = []
+  if tests is None:
+    tests = []
+  if generators is None:
+    generators = []
+  if archives is None:
+    archives = []
+
   with api.step.nest('launch builds') as presentation:
     tasks = api.shard_util_v2.schedule_builds(builds, presentation)
   with api.step.nest('collect builds') as presentation:
@@ -75,13 +92,6 @@
   )
 
   # Run tests
-  tests = api.properties.get('tests')
-  if tests is None:
-    tests = api.json.read(
-        'Read build config file',
-        config_path,
-        step_test_data=lambda: api.json.test_api.output({})
-    ).json.output.get('tests', [])
   with api.step.nest('launch tests') as presentation:
     tasks = api.shard_util_v2.schedule_tests(tests, build_results, presentation)
   with api.step.nest('collect tests') as presentation:
@@ -95,15 +105,8 @@
 
 
   # Global generators
-  generators = api.properties.get('generators')
-  if generators is None:
-    generators = api.json.read(
-        'Read build config file',
-        config_path,
-        step_test_data=lambda: api.json.test_api.output({})
-    ).json.output.get('generators', [])
-  if generators:
-    # Generators require a full engine checkout.
+  if generators or archives:
+    # Generators and archives require a full engine checkout.
     full_engine_checkout = api.path['cache'].join('builder')
     api.file.ensure_directory('Ensure full engine checkout folder', full_engine_checkout)
     clobber = api.properties.get('clobber', True)
@@ -114,6 +117,8 @@
         full_engine_checkout, env, env_prefixes, clobber,
         custom_vars=gclient_vars
     )
+
+  if generators:
     # Download sub-builds
     out_builds_path = full_engine_checkout.join('src', 'out')
     api.file.rmtree('Clobber build download folder', out_builds_path)
@@ -140,27 +145,26 @@
     api.file.listdir('Final List checkout', full_engine_checkout.join('src', 'out'), recursive=True)
     api.file.listdir('Final List checkout 2', full_engine_checkout.join('src', 'flutter', 'sky'), recursive=True)
   # Global archives
-  archives = api.properties.get('archives')
-  if archives is None:
-    archives = api.json.read(
-        'Read build config file',
-        config_path,
-        step_test_data=lambda: api.json.test_api.output({})
-    ).json.output.get('archives', [])
-  # Global archives are stored in out folder from full_engine_checkout inside release, debug or profile
-  # depending of the runtime mode. So far we are uploading files only.
-  bucket = 'flutter_archives_v2'
-  for archive in archives:
-    source = full_engine_checkout.join('src', archive.get('source'))
-    commit = api.repo_util.get_commit(full_engine_checkout.join('src', 'flutter'))
-    artifact_path = 'flutter_infra_release/flutter/%s/%s' % (commit, archive.get('destination'))
-    api.gsutil.upload(
-        source=source,
-        bucket=bucket,
-        dest=artifact_path,
-        args=['-r'],
-        name=archive.get('name'),
-    )
+  if archives:
+    # Global archives are stored in out folder from full_engine_checkout inside
+    # release, debug or profile depending on the runtime mode.
+    # So far we are uploading files only.
+    bucket = 'flutter_archives_v2'
+    for archive in archives:
+      source = full_engine_checkout.join('src', archive.get('source'))
+      commit = api.repo_util.get_commit(
+          full_engine_checkout.join('src', 'flutter')
+      )
+      artifact_path = 'flutter_infra_release/flutter/%s/%s' % (
+          commit, archive.get('destination')
+      )
+      api.gsutil.upload(
+          source=source,
+          bucket=bucket,
+          dest=artifact_path,
+          args=['-r'],
+          name=archive.get('name'),
+      )
 
 
 def _run_global_generator(api, generator_task, full_engine_checkout):
@@ -216,7 +220,13 @@
   yield api.test(
       'basic_mac',
       api.platform.name('mac'),
-      api.properties(builds=builds, tests=[], generators=generators, archives=archives, environment='Staging'),
+      api.properties(
+          builds=builds,
+          tests=[],
+          generators=generators,
+          archives=archives,
+          environment='Staging'
+      ),
       api.buildbucket.try_build(
           project='proj',
           builder='try-builder',
@@ -234,7 +244,9 @@
   yield api.test(
       'basic_linux',
       api.platform.name('linux'),
-      api.properties(builds=builds, tests=[], generators=generators, environment='Staging'),
+      api.properties(
+          builds=builds, generators=generators, environment='Staging'
+      ),
       api.buildbucket.try_build(
           project='proj',
           builder='try-builder',
@@ -251,11 +263,11 @@
 
   yield api.test(
       'config_from_file',
-      api.properties(environment='Staging'),
+      api.properties(config_name='config_name', environment='Staging'),
       api.buildbucket.try_build(
           project='proj',
           builder='try-builder',
-          git_repo='https://github.com/repo/a',
+          git_repo='https://flutter.googlesource.com/mirrors/engine',
           revision='a' * 40,
           build_number=123,
       ),
@@ -266,8 +278,44 @@
       ),
       api.step_data(
           'Read build config file',
-          api.json.output({'builds': builds})),
+          api.file.read_json({'builds': builds, 'archives': archives})
+      ),
+  )
+
+  yield api.test(
+      'overridden_config_from_file',
+      api.properties(
+          config_name='overridden_config_name',
+          archives=[],
+          generators=[],
+          environment='Staging'
+      ),
+      api.buildbucket.try_build(
+          project='proj',
+          builder='try-builder',
+          git_repo='https://flutter.googlesource.com/mirrors/engine',
+          revision='a' * 40,
+          build_number=123,
+      ),
       api.step_data(
-          'Read build config file (2)',
-          api.json.output({'builds': builds})),
+          'Read build config file', api.file.read_json({'archives': archives})
+      ),
+  )
+
+  yield api.test(
+      'monorepo_linux',
+      api.platform.name('linux'),
+      api.properties(builds=builds, environment='Staging'),
+      api.buildbucket.try_build(
+          project='proj',
+          builder='try-builder',
+          git_repo='https://dart.googlesource.com/monorepo',
+          revision='a' * 40,
+          build_number=123,
+      ),
+      api.shard_util_v2.child_build_steps(
+          builds=[try_subbuild1],
+          launch_step="launch builds",
+          collect_step="collect builds",
+      ),
   )