diff --git a/dev/automated_tests/pubspec.yaml b/dev/automated_tests/pubspec.yaml
index 0e01c47595e..74cdeb38811 100644
--- a/dev/automated_tests/pubspec.yaml
+++ b/dev/automated_tests/pubspec.yaml
@@ -9,7 +9,7 @@ dependencies:
     sdk: flutter
   flutter_test:
     sdk: flutter
-  test: 1.5.2
+  test: 1.5.3
 
   analyzer: 0.33.6+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   args: 1.5.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -56,7 +56,7 @@ dependencies:
   string_scanner: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   term_glyph: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   test_api: 0.2.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   typed_data: 1.1.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   vector_math: 2.0.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -68,4 +68,4 @@ dependencies:
 flutter:
   uses-material-design: true
 
-# PUBSPEC CHECKSUM: e195
+# PUBSPEC CHECKSUM: 25f2
diff --git a/dev/benchmarks/complex_layout/pubspec.yaml b/dev/benchmarks/complex_layout/pubspec.yaml
index 3c6784c9e92..8f4fbe53a14 100644
--- a/dev/benchmarks/complex_layout/pubspec.yaml
+++ b/dev/benchmarks/complex_layout/pubspec.yaml
@@ -40,7 +40,7 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  test: 1.5.2
+  test: 1.5.3
 
   analyzer: 0.33.6+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   args: 1.5.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -74,7 +74,7 @@ dev_dependencies:
   source_maps: 0.10.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   string_scanner: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   test_api: 0.2.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   watcher: 0.9.7+10 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   yaml: 2.1.15 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -85,4 +85,4 @@ flutter:
     - packages/flutter_gallery_assets/people/square/ali.png
     - packages/flutter_gallery_assets/places/india_chettinad_silk_maker.png
 
-# PUBSPEC CHECKSUM: b266
+# PUBSPEC CHECKSUM: 39c3
diff --git a/dev/benchmarks/macrobenchmarks/pubspec.yaml b/dev/benchmarks/macrobenchmarks/pubspec.yaml
index 01d15fead71..12523642453 100644
--- a/dev/benchmarks/macrobenchmarks/pubspec.yaml
+++ b/dev/benchmarks/macrobenchmarks/pubspec.yaml
@@ -40,7 +40,7 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  test: 1.5.2
+  test: 1.5.3
 
   analyzer: 0.33.6+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   args: 1.5.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -74,7 +74,7 @@ dev_dependencies:
   source_maps: 0.10.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   string_scanner: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   test_api: 0.2.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   watcher: 0.9.7+10 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   yaml: 2.1.15 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -82,4 +82,4 @@ dev_dependencies:
 flutter:
   uses-material-design: true
 
-# PUBSPEC CHECKSUM: b266
+# PUBSPEC CHECKSUM: 39c3
diff --git a/dev/benchmarks/microbenchmarks/pubspec.yaml b/dev/benchmarks/microbenchmarks/pubspec.yaml
index 698c30bac03..f7317d62717 100644
--- a/dev/benchmarks/microbenchmarks/pubspec.yaml
+++ b/dev/benchmarks/microbenchmarks/pubspec.yaml
@@ -13,7 +13,7 @@ dependencies:
     sdk: flutter
   stocks:
     path: ../../../examples/stocks
-  test: 1.5.2
+  test: 1.5.3
 
   analyzer: 0.33.6+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   args: 1.5.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -64,7 +64,7 @@ dependencies:
   string_scanner: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   term_glyph: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   test_api: 0.2.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   typed_data: 1.1.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   vector_math: 2.0.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -76,4 +76,4 @@ dependencies:
 flutter:
   uses-material-design: true
 
-# PUBSPEC CHECKSUM: 61eb
+# PUBSPEC CHECKSUM: fd49
diff --git a/dev/bots/pubspec.yaml b/dev/bots/pubspec.yaml
index f13e21ad69c..c9e4b5c98b0 100644
--- a/dev/bots/pubspec.yaml
+++ b/dev/bots/pubspec.yaml
@@ -13,7 +13,7 @@ dependencies:
   platform: 2.2.0
   http: 0.12.0+1
   http_parser: 3.1.3
-  test: 1.5.2
+  test: 1.5.3
 
   analyzer: 0.33.6+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   async: 2.0.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -55,7 +55,7 @@ dependencies:
   stream_channel: 1.6.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   string_scanner: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   term_glyph: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   typed_data: 1.1.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   vm_service_client: 0.2.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -67,4 +67,4 @@ dev_dependencies:
   mockito: 4.0.0
   test_api: 0.2.2
 
-# PUBSPEC CHECKSUM: 4e3a
+# PUBSPEC CHECKSUM: ca97
diff --git a/dev/devicelab/pubspec.yaml b/dev/devicelab/pubspec.yaml
index 6c2a62b8a30..276a75842a7 100644
--- a/dev/devicelab/pubspec.yaml
+++ b/dev/devicelab/pubspec.yaml
@@ -37,7 +37,7 @@ dependencies:
 
 dev_dependencies:
   # See packages/flutter_test/pubspec.yaml for why we're pinning this version.
-  test: 1.5.2
+  test: 1.5.3
 
   analyzer: 0.33.6+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   boolean_selector: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -69,9 +69,9 @@ dev_dependencies:
   source_maps: 0.10.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   string_scanner: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   test_api: 0.2.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   watcher: 0.9.7+10 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   yaml: 2.1.15 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
 
-# PUBSPEC CHECKSUM: cf24
+# PUBSPEC CHECKSUM: bc81
diff --git a/dev/integration_tests/android_semantics_testing/pubspec.yaml b/dev/integration_tests/android_semantics_testing/pubspec.yaml
index 5acaaa7fef7..7b443fc091e 100644
--- a/dev/integration_tests/android_semantics_testing/pubspec.yaml
+++ b/dev/integration_tests/android_semantics_testing/pubspec.yaml
@@ -6,7 +6,7 @@ dependencies:
     sdk: flutter
   flutter_driver:
     sdk: flutter
-  test: 1.5.2
+  test: 1.5.3
 
   analyzer: 0.33.6+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   args: 1.5.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -54,7 +54,7 @@ dependencies:
   string_scanner: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   term_glyph: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   test_api: 0.2.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   typed_data: 1.1.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   vector_math: 2.0.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -66,4 +66,4 @@ dependencies:
 flutter:
   uses-material-design: true
 
-# PUBSPEC CHECKSUM: 13de
+# PUBSPEC CHECKSUM: 7b3c
diff --git a/dev/integration_tests/android_views/pubspec.yaml b/dev/integration_tests/android_views/pubspec.yaml
index c910f580819..7f0586ff97f 100644
--- a/dev/integration_tests/android_views/pubspec.yaml
+++ b/dev/integration_tests/android_views/pubspec.yaml
@@ -37,7 +37,7 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  test: 1.5.2
+  test: 1.5.3
 
   analyzer: 0.33.6+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   args: 1.5.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -71,7 +71,7 @@ dev_dependencies:
   source_maps: 0.10.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   string_scanner: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   test_api: 0.2.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   watcher: 0.9.7+10 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   yaml: 2.1.15 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -79,4 +79,4 @@ dev_dependencies:
 flutter:
   uses-material-design: true
 
-# PUBSPEC CHECKSUM: eb90
+# PUBSPEC CHECKSUM: 1bed
diff --git a/dev/integration_tests/channels/pubspec.yaml b/dev/integration_tests/channels/pubspec.yaml
index 94834d90abe..2142a56e625 100644
--- a/dev/integration_tests/channels/pubspec.yaml
+++ b/dev/integration_tests/channels/pubspec.yaml
@@ -10,7 +10,7 @@ dependencies:
     sdk: flutter
   flutter_driver:
     sdk: flutter
-  test: 1.5.2
+  test: 1.5.3
 
   analyzer: 0.33.6+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   args: 1.5.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -58,7 +58,7 @@ dependencies:
   string_scanner: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   term_glyph: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   test_api: 0.2.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   typed_data: 1.1.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   vector_math: 2.0.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -70,4 +70,4 @@ dependencies:
 flutter:
   uses-material-design: true
 
-# PUBSPEC CHECKSUM: 13de
+# PUBSPEC CHECKSUM: 7b3c
diff --git a/dev/integration_tests/external_ui/pubspec.yaml b/dev/integration_tests/external_ui/pubspec.yaml
index 69c58bb43db..7492db33c2d 100644
--- a/dev/integration_tests/external_ui/pubspec.yaml
+++ b/dev/integration_tests/external_ui/pubspec.yaml
@@ -10,7 +10,7 @@ dependencies:
     sdk: flutter
   flutter_driver:
     sdk: flutter
-  test: 1.5.2
+  test: 1.5.3
 
   analyzer: 0.33.6+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   args: 1.5.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -58,7 +58,7 @@ dependencies:
   string_scanner: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   term_glyph: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   test_api: 0.2.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   typed_data: 1.1.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   vector_math: 2.0.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -70,4 +70,4 @@ dependencies:
 flutter:
   uses-material-design: true
 
-# PUBSPEC CHECKSUM: 13de
+# PUBSPEC CHECKSUM: 7b3c
diff --git a/dev/integration_tests/flavors/pubspec.yaml b/dev/integration_tests/flavors/pubspec.yaml
index 10e51b55083..656eb34a969 100644
--- a/dev/integration_tests/flavors/pubspec.yaml
+++ b/dev/integration_tests/flavors/pubspec.yaml
@@ -10,7 +10,7 @@ dependencies:
     sdk: flutter
   flutter_driver:
     sdk: flutter
-  test: 1.5.2
+  test: 1.5.3
 
   analyzer: 0.33.6+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   args: 1.5.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -58,7 +58,7 @@ dependencies:
   string_scanner: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   term_glyph: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   test_api: 0.2.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   typed_data: 1.1.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   vector_math: 2.0.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -70,4 +70,4 @@ dependencies:
 flutter:
   uses-material-design: true
 
-# PUBSPEC CHECKSUM: 13de
+# PUBSPEC CHECKSUM: 7b3c
diff --git a/dev/integration_tests/platform_interaction/pubspec.yaml b/dev/integration_tests/platform_interaction/pubspec.yaml
index 40b77b21e55..ba266fc5cc5 100644
--- a/dev/integration_tests/platform_interaction/pubspec.yaml
+++ b/dev/integration_tests/platform_interaction/pubspec.yaml
@@ -10,7 +10,7 @@ dependencies:
     sdk: flutter
   flutter_driver:
     sdk: flutter
-  test: 1.5.2
+  test: 1.5.3
 
   analyzer: 0.33.6+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   args: 1.5.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -58,7 +58,7 @@ dependencies:
   string_scanner: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   term_glyph: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   test_api: 0.2.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   typed_data: 1.1.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   vector_math: 2.0.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -70,4 +70,4 @@ dependencies:
 flutter:
   uses-material-design: true
 
-# PUBSPEC CHECKSUM: 13de
+# PUBSPEC CHECKSUM: 7b3c
diff --git a/dev/integration_tests/ui/pubspec.yaml b/dev/integration_tests/ui/pubspec.yaml
index 4beb8bab032..ea71ee6bc93 100644
--- a/dev/integration_tests/ui/pubspec.yaml
+++ b/dev/integration_tests/ui/pubspec.yaml
@@ -11,7 +11,7 @@ dependencies:
     sdk: flutter
   flutter_driver:
     sdk: flutter
-  test: 1.5.2
+  test: 1.5.3
 
   analyzer: 0.33.6+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   archive: 2.0.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -60,7 +60,7 @@ dependencies:
   stream_channel: 1.6.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   string_scanner: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   term_glyph: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   typed_data: 1.1.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   vector_math: 2.0.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -80,4 +80,4 @@ dev_dependencies:
 flutter:
   uses-material-design: true
 
-# PUBSPEC CHECKSUM: 54f5
+# PUBSPEC CHECKSUM: e153
diff --git a/dev/snippets/pubspec.yaml b/dev/snippets/pubspec.yaml
index 9be4f5119e5..8e37cf03568 100644
--- a/dev/snippets/pubspec.yaml
+++ b/dev/snippets/pubspec.yaml
@@ -43,7 +43,7 @@ dependencies:
   yaml: 2.1.15 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
 
 dev_dependencies:
-  test: 1.5.2
+  test: 1.5.3
 
   boolean_selector: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   http: 0.12.0+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -68,7 +68,7 @@ dev_dependencies:
   stack_trace: 1.9.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   stream_channel: 1.6.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   test_api: 0.2.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   vm_service_client: 0.2.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   web_socket_channel: 1.0.9 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
 
@@ -101,4 +101,4 @@ executables:
   vm_service_client: 0.2.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   web_socket_channel: 1.0.9 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
 
-# PUBSPEC CHECKSUM: 48f7
+# PUBSPEC CHECKSUM: bb55
diff --git a/examples/catalog/pubspec.yaml b/examples/catalog/pubspec.yaml
index 03703762bd6..a496ead3654 100644
--- a/examples/catalog/pubspec.yaml
+++ b/examples/catalog/pubspec.yaml
@@ -20,7 +20,7 @@ dev_dependencies:
     sdk: flutter
   flutter_driver:
     sdk: flutter
-  test: 1.5.2
+  test: 1.5.3
 
   analyzer: 0.33.6+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   args: 1.5.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -66,7 +66,7 @@ dev_dependencies:
   string_scanner: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   term_glyph: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   test_api: 0.2.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   vm_service_client: 0.2.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   watcher: 0.9.7+10 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -76,4 +76,4 @@ dev_dependencies:
 flutter:
   uses-material-design: true
 
-# PUBSPEC CHECKSUM: c6c7
+# PUBSPEC CHECKSUM: d225
diff --git a/examples/flutter_gallery/pubspec.yaml b/examples/flutter_gallery/pubspec.yaml
index 239ede4dfb9..e1ba254c4c3 100644
--- a/examples/flutter_gallery/pubspec.yaml
+++ b/examples/flutter_gallery/pubspec.yaml
@@ -10,7 +10,7 @@ dependencies:
   collection: 1.14.11
   device_info: 0.4.0
   intl: 0.15.7
-  connectivity: 0.4.0
+  connectivity: 0.4.0+1
   string_scanner: 1.0.4
   url_launcher: 5.0.0
   cupertino_icons: 0.1.2
@@ -36,7 +36,7 @@ dev_dependencies:
     sdk: flutter
   flutter_goldens:
     sdk: flutter
-  test: 1.5.2
+  test: 1.5.3
 
   analyzer: 0.33.6+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   args: 1.5.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -79,7 +79,7 @@ dev_dependencies:
   stack_trace: 1.9.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   stream_channel: 1.6.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   test_api: 0.2.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   vm_service_client: 0.2.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   watcher: 0.9.7+10 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -242,4 +242,4 @@ flutter:
         - asset: packages/flutter_gallery_assets/fonts/private/googlesans/GoogleSansDisplay-Regular.ttf
           weight: 400
 
-# PUBSPEC CHECKSUM: 2c0e
+# PUBSPEC CHECKSUM: b3c7
diff --git a/examples/platform_channel/pubspec.yaml b/examples/platform_channel/pubspec.yaml
index a0ab404035c..42df5e2c28d 100644
--- a/examples/platform_channel/pubspec.yaml
+++ b/examples/platform_channel/pubspec.yaml
@@ -18,7 +18,7 @@ dev_dependencies:
     sdk: flutter
   flutter_driver:
     sdk: flutter
-  test: 1.5.2
+  test: 1.5.3
 
   analyzer: 0.33.6+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   args: 1.5.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -65,7 +65,7 @@ dev_dependencies:
   string_scanner: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   term_glyph: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   test_api: 0.2.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test_core: 0.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.2.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   vm_service_client: 0.2.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   watcher: 0.9.7+10 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -75,4 +75,4 @@ dev_dependencies:
 flutter:
   uses-material-design: true
 
-# PUBSPEC CHECKSUM: c6c7
+# PUBSPEC CHECKSUM: d225
diff --git a/packages/flutter_build/lib/src/kernel_builder.dart b/packages/flutter_build/lib/src/kernel_builder.dart
index 1ee28329776..65f873dd335 100644
--- a/packages/flutter_build/lib/src/kernel_builder.dart
+++ b/packages/flutter_build/lib/src/kernel_builder.dart
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// Note: this Builder does not run in the same process as the flutter_tool, so
+// the DI provided getters such as `fs` will not work.
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
@@ -14,7 +16,6 @@ import 'package:path/path.dart' as path;
 
 const String _kFlutterDillOutputExtension = '.app.dill';
 const String _kPackagesExtension = '.packages';
-const String multiRootScheme = 'org-dartlang-app';
 
 /// A builder which creates a kernel and packages file for a Flutter app.
 ///
@@ -235,39 +236,47 @@ class _StdoutHandler {
   }
 }
 
+
+class _CompilerOutput {
+  const _CompilerOutput(this.outputFilename, this.errorCount);
+
+  final String outputFilename;
+  final int errorCount;
+}
+
 /// Converts filesystem paths to package URIs.
 class _PackageUriMapper {
-  _PackageUriMapper(String scriptPath, String packagesPath, this.fileSystemScheme, this.fileSystemRoots) {
+  _PackageUriMapper(String scriptPath, String packagesPath, String fileSystemScheme, List<String> fileSystemRoots) {
     final List<int> bytes = File(path.absolute(packagesPath)).readAsBytesSync();
     final Map<String, Uri> packageMap = packages_file.parse(bytes, Uri.file(packagesPath, windows: Platform.isWindows));
     final String scriptUri = Uri.file(scriptPath, windows: Platform.isWindows).toString();
+
     for (String packageName in packageMap.keys) {
       final String prefix = packageMap[packageName].toString();
       if (fileSystemScheme != null && fileSystemRoots != null && prefix.contains(fileSystemScheme)) {
         _packageName = packageName;
-        _uriPrefix = fileSystemRoots.map((String name) => Uri.file('$name/lib/', windows: Platform.isWindows).toString()).toList();
+        _uriPrefixes = fileSystemRoots
+          .map((String name) => Uri.file('$name/lib/', windows: Platform.isWindows).toString())
+          .toList();
         return;
       }
       if (scriptUri.startsWith(prefix)) {
         _packageName = packageName;
-        _uriPrefix = <String>[prefix];
+        _uriPrefixes = <String>[prefix];
         return;
       }
     }
   }
 
-  final String fileSystemScheme;
-  final List<String> fileSystemRoots;
-
   String _packageName;
-  List<String> _uriPrefix;
+  List<String> _uriPrefixes;
 
   Uri map(String scriptPath) {
     if (_packageName == null) {
       return null;
     }
     final String scriptUri = Uri.file(scriptPath, windows: Platform.isWindows).toString();
-    for (String uriPrefix in _uriPrefix) {
+    for (String uriPrefix in _uriPrefixes) {
       if (scriptUri.startsWith(uriPrefix)) {
         return Uri.parse('package:$_packageName/${scriptUri.substring(uriPrefix.length)}');
       }
@@ -279,10 +288,3 @@ class _PackageUriMapper {
     return _PackageUriMapper(scriptPath, packagesPath, fileSystemScheme, fileSystemRoots).map(scriptPath);
   }
 }
-
-class _CompilerOutput {
-  const _CompilerOutput(this.outputFilename, this.errorCount);
-
-  final String outputFilename;
-  final int errorCount;
-}
diff --git a/packages/flutter_build/pubspec.yaml b/packages/flutter_build/pubspec.yaml
index 1784a936426..bd81dc578cb 100644
--- a/packages/flutter_build/pubspec.yaml
+++ b/packages/flutter_build/pubspec.yaml
@@ -7,7 +7,7 @@ environment:
 dependencies:
   # To update these, use "flutter update-packages --force-upgrade".
   build: 1.1.0
-  build_modules: 1.0.4
+  build_modules: 1.0.6
   package_config: 1.0.5
   path: 1.6.2
 
@@ -33,7 +33,7 @@ dependencies:
   pedantic: 1.4.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   plugin: 0.2.0+3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   pool: 1.4.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  protobuf: 0.13.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  protobuf: 0.13.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   pub_semver: 1.4.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   pubspec_parse: 0.1.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   scratch_space: 0.0.3+2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -50,4 +50,4 @@ dartdoc:
   # Exclude this package from the hosted API docs.
   nodoc: true
 
-# PUBSPEC CHECKSUM: ec31
+# PUBSPEC CHECKSUM: 1f34
diff --git a/packages/flutter_tools/lib/src/build_runner/build_runner.dart b/packages/flutter_tools/lib/src/build_runner/build_runner.dart
index 3c062cfeb07..68591c079bd 100644
--- a/packages/flutter_tools/lib/src/build_runner/build_runner.dart
+++ b/packages/flutter_tools/lib/src/build_runner/build_runner.dart
@@ -4,19 +4,22 @@
 
 import 'dart:async';
 
+import 'package:build_runner_core/build_runner_core.dart';
 import 'package:meta/meta.dart';
 
 import '../artifacts.dart';
 import '../base/context.dart';
 import '../base/file_system.dart';
 import '../base/io.dart';
+import '../base/logger.dart';
 import '../base/platform.dart';
 import '../base/process_manager.dart';
 import '../cache.dart';
 import '../convert.dart';
-import '../dart/package_map.dart';
+import '../dart/pub.dart';
 import '../globals.dart';
 import '../project.dart';
+import 'build_script_generator.dart';
 
 /// The [BuildRunnerFactory] instance.
 BuildRunnerFactory get buildRunnerFactory => context[BuildRunnerFactory];
@@ -26,17 +29,8 @@ BuildRunnerFactory get buildRunnerFactory => context[BuildRunnerFactory];
 /// This requires both an experimental opt in via the environment variable
 /// 'FLUTTER_EXPERIMENTAL_BUILD' and that the project itself has a
 /// dependency on the package 'flutter_build' and 'build_runner.'
-FutureOr<bool> get experimentalBuildEnabled async {
-  if (_experimentalBuildEnabled != null) {
-    return _experimentalBuildEnabled;
-  }
-  final bool flagEnabled = platform.environment['FLUTTER_EXPERIMENTAL_BUILD']?.toLowerCase() == 'true';
-  if (!flagEnabled) {
-    return _experimentalBuildEnabled = false;
-  }
-  final FlutterProject flutterProject = await FlutterProject.current();
-  final Map<String, Uri> packages = PackageMap(flutterProject.packagesFile.path).map;
-  return _experimentalBuildEnabled = packages.containsKey('flutter_build') && packages.containsKey('build_runner');
+bool get experimentalBuildEnabled {
+  return _experimentalBuildEnabled ??= platform.environment['FLUTTER_EXPERIMENTAL_BUILD']?.toLowerCase() == 'true';
 }
 bool _experimentalBuildEnabled;
 
@@ -74,53 +68,69 @@ class BuildRunner {
     @required String mainPath,
     @required List<String> extraFrontEndOptions,
   }) async {
+    await generateBuildScript();
     final FlutterProject flutterProject = await FlutterProject.current();
     final String frontendServerPath = artifacts.getArtifactPath(
       Artifact.frontendServerSnapshotForEngineDartSdk
     );
-    final String pubExecutable = fs.path.join(Cache.flutterRoot, 'bin', 'cache', 'dart-sdk','bin', 'pub');
     final String sdkRoot = artifacts.getArtifactPath(Artifact.flutterPatchedSdkPath);
     final String engineDartBinaryPath = artifacts.getArtifactPath(Artifact.engineDartBinary);
     final String packagesPath = flutterProject.packagesFile.absolute.path;
-    final Process process = await processManager.start(<String>[
-      '$pubExecutable',
-      'run',
-      'build_runner',
-      'build',
-      '--define', 'flutter_build|kernel=disabled=false',
-      '--define', 'flutter_build|kernel=aot=$aot',
-      '--define', 'flutter_build|kernel=linkPlatformKernelIn=$linkPlatformKernelIn',
-      '--define', 'flutter_build|kernel=trackWidgetCreation=$trackWidgetCreation',
-      '--define', 'flutter_build|kernel=targetProductVm=$targetProductVm',
-      '--define', 'flutter_build|kernel=mainPath=$mainPath',
-      '--define', 'flutter_build|kernel=packagesPath=$packagesPath',
-      '--define', 'flutter_build|kernel=sdkRoot=$sdkRoot',
-      '--define', 'flutter_build|kernel=frontendServerPath=$frontendServerPath',
-      '--define', 'flutter_build|kernel=engineDartBinaryPath=$engineDartBinaryPath',
-      '--define', 'flutter_build|kernel=extraFrontEndOptions=${extraFrontEndOptions ?? const <String>[]}',
-    ]);
-    process.stdout
-      .transform(utf8.decoder)
-      .transform(const LineSplitter())
-      .listen(_handleOutput);
-    process.stderr
-      .transform(utf8.decoder)
-      .transform(const LineSplitter())
-      .listen(_handleError);
-    final int exitCode = await process.exitCode;
-    if (exitCode != 0) {
-      throw Exception('build_runner exited with non-zero exit code: $exitCode');
+    final String buildScript = flutterProject
+        .dartTool
+        .childDirectory('build')
+        .childDirectory('entrypoint')
+        .childFile('build.dart')
+        .path;
+    final String scriptPackagesPath = flutterProject
+        .dartTool
+        .childDirectory('flutter_tool')
+        .childFile('.packages')
+        .path;
+    final String dartPath = fs.path.join(Cache.flutterRoot, 'bin', 'cache', 'dart-sdk', 'bin', 'dart');
+    final Status status = logger.startProgress('running builders...', timeout: null);
+    try {
+      final Process buildProcess = await processManager.start(<String>[
+        dartPath,
+        '--packages=$scriptPackagesPath',
+        buildScript,
+        'build',
+        '--define', 'flutter_build|kernel=disabled=false',
+        '--define', 'flutter_build|kernel=aot=$aot',
+        '--define', 'flutter_build|kernel=linkPlatformKernelIn=$linkPlatformKernelIn',
+        '--define', 'flutter_build|kernel=trackWidgetCreation=$trackWidgetCreation',
+        '--define', 'flutter_build|kernel=targetProductVm=$targetProductVm',
+        '--define', 'flutter_build|kernel=mainPath=$mainPath',
+        '--define', 'flutter_build|kernel=packagesPath=$packagesPath',
+        '--define', 'flutter_build|kernel=sdkRoot=$sdkRoot',
+        '--define', 'flutter_build|kernel=frontendServerPath=$frontendServerPath',
+        '--define', 'flutter_build|kernel=engineDartBinaryPath=$engineDartBinaryPath',
+        '--define', 'flutter_build|kernel=extraFrontEndOptions=${extraFrontEndOptions ?? const <String>[]}',
+      ]);
+      buildProcess
+          .stdout
+          .transform(utf8.decoder)
+          .transform(const LineSplitter())
+          .listen(printStatus);
+      buildProcess
+          .stderr
+          .transform(utf8.decoder)
+          .transform(const LineSplitter())
+          .listen(printError);
+      await buildProcess.exitCode;
+    } finally {
+      status.stop();
     }
     /// We don't check for this above because it might be generated for the
     /// first time by invoking the build.
     final Directory dartTool = flutterProject.dartTool;
     final String projectName = flutterProject.manifest.appName;
     final Directory generatedDirectory = dartTool
-      .absolute
-      .childDirectory('build')
-      .childDirectory('generated')
-      .childDirectory(projectName);
-    if (!await generatedDirectory.exists()) {
+        .absolute
+        .childDirectory('build')
+        .childDirectory('generated')
+        .childDirectory(projectName);
+    if (!generatedDirectory.existsSync()) {
       throw Exception('build_runner cannot find generated directory');
     }
     final String relativeMain = fs.path.relative(mainPath, from: flutterProject.directory.path);
@@ -130,18 +140,66 @@ class BuildRunner {
     final File dillFile = fs.file(
       fs.path.join(generatedDirectory.path, fs.path.setExtension(relativeMain, '.app.dill'))
     );
-    if (!await packagesFile.exists() || !await dillFile.exists()) {
+    if (!packagesFile.existsSync() || !dillFile.existsSync()) {
       throw Exception('build_runner did not produce output at expected location: ${dillFile.path} missing');
     }
     return BuildResult(packagesFile, dillFile);
   }
 
-  void _handleOutput(String line) {
-    printTrace(line);
+  /// Invalidates a generated build script by deleting it.
+  ///
+  /// Must be called any time a pubspec file update triggers a corresponding change
+  /// in .packages.
+  Future<void> invalidateBuildScript() async {
+    final FlutterProject flutterProject = await FlutterProject.current();
+    final File buildScript = flutterProject.dartTool
+        .absolute
+        .childDirectory('flutter_tool')
+        .childFile('build.dart');
+    if (!buildScript.existsSync()) {
+      return;
+    }
+    await buildScript.delete();
   }
 
-  void _handleError(String line) {
-    printError(line);
+  // Generates a synthetic package under .dart_tool/flutter_tool which is in turn
+  // used to generate a build script.
+  Future<void> generateBuildScript() async {
+    final FlutterProject flutterProject = await FlutterProject.current();
+    final String generatedDirectory = fs.path.join(flutterProject.dartTool.path, 'flutter_tool');
+    final String resultScriptPath = fs.path.join(flutterProject.dartTool.path, 'build', 'entrypoint', 'build.dart');
+    if (fs.file(resultScriptPath).existsSync()) {
+      return;
+    }
+    final Status status = logger.startProgress('generating build script...', timeout: null);
+    try {
+      fs.directory(generatedDirectory).createSync(recursive: true);
+
+      final File syntheticPubspec = fs.file(fs.path.join(generatedDirectory, 'pubspec.yaml'));
+      final StringBuffer stringBuffer = StringBuffer();
+
+      stringBuffer.writeln('name: synthetic_example');
+      stringBuffer.writeln('dependencies:');
+      for (String builder in await flutterProject.builders) {
+        stringBuffer.writeln('  $builder: any');
+      }
+      stringBuffer.writeln('  build_runner: any');
+      stringBuffer.writeln('  flutter_build:');
+      stringBuffer.writeln('    sdk: flutter');
+      await syntheticPubspec.writeAsString(stringBuffer.toString());
+
+      await pubGet(
+        context: PubContext.pubGet,
+        directory: generatedDirectory,
+        upgrade: false,
+        checkLastModified: false,
+      );
+      final PackageGraph packageGraph = PackageGraph.forPath(syntheticPubspec.parent.path);
+      final BuildScriptGenerator buildScriptGenerator = buildScriptGeneratorFactory.create(flutterProject, packageGraph);
+      await buildScriptGenerator.generateBuildScript();
+    } finally {
+      status.stop();
+    }
   }
 }
 
diff --git a/packages/flutter_tools/lib/src/build_runner/build_script_generator.dart b/packages/flutter_tools/lib/src/build_runner/build_script_generator.dart
new file mode 100644
index 00000000000..1467872ace4
--- /dev/null
+++ b/packages/flutter_tools/lib/src/build_runner/build_script_generator.dart
@@ -0,0 +1,283 @@
+// Copyright 201 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:async';
+
+import 'package:build_runner_core/build_runner_core.dart';
+import 'package:build/build.dart' show BuilderOptions;
+import 'package:build_config/build_config.dart';
+import 'package:code_builder/code_builder.dart';
+import 'package:dart_style/dart_style.dart';
+import 'package:graphs/graphs.dart';
+
+import '../base/common.dart';
+import '../base/context.dart';
+import '../base/file_system.dart';
+import '../project.dart';
+
+BuildScriptGeneratorFactory get buildScriptGeneratorFactory => context[BuildScriptGeneratorFactory];
+
+class BuildScriptGeneratorFactory {
+  const BuildScriptGeneratorFactory();
+
+  /// Creates a [BuildScriptGenerator] for the current flutter project.
+  BuildScriptGenerator create(FlutterProject flutterProject, PackageGraph packageGraph) {
+    return BuildScriptGenerator(flutterProject, packageGraph);
+  }
+}
+
+/// Generates a build_script for the current flutter project.
+class BuildScriptGenerator {
+  const BuildScriptGenerator(this.flutterProject, this.packageGraph);
+
+  final FlutterProject flutterProject;
+  final PackageGraph packageGraph;
+
+  /// Generate a build script for the curent flutter project.
+  ///
+  /// Requires the project to have a pubspec.yaml.
+  Future<void> generateBuildScript() async {
+    final Iterable<Expression> builders = await _findBuilderApplications();
+    final Library library = Library((LibraryBuilder libraryBuilder) => libraryBuilder.body.addAll(<Spec>[
+      literalList(builders, refer('BuilderApplication', 'package:build_runner_core/build_runner_core.dart'))
+        .assignFinal('_builders')
+        .statement,
+      _createMain()
+    ]));
+    final DartEmitter emitter = DartEmitter(Allocator.simplePrefixing());
+    try {
+      final String location = fs.path.join(flutterProject.dartTool.path, 'build', 'entrypoint', 'build.dart');
+      final String result = DartFormatter().format('''
+        // ignore_for_file: directives_ordering
+        ${library.accept(emitter)}''');
+      final File output = fs.file(location);
+      await output.create(recursive: true);
+      await fs.file(location).writeAsString(result);
+    } on FormatterException {
+      throwToolExit('Generated build script could not be parsed. '
+        'This is likely caused by a misconfigured builder definition.');
+    }
+  }
+
+  /// Finds expressions to create all the `BuilderApplication` instances that
+  /// should be applied packages in the build.
+  ///
+  /// Adds `apply` expressions based on the BuildefDefinitions from any package
+  /// which has a `build.yaml`.
+  Future<Iterable<Expression>> _findBuilderApplications() async {
+    final List<Expression> builderApplications = <Expression>[];
+    final Iterable<PackageNode> orderedPackages = stronglyConnectedComponents<PackageNode>(
+      <PackageNode>[packageGraph.root],
+      (PackageNode node) => node.dependencies,
+      equals: (PackageNode a, PackageNode b) => a.name == b.name,
+      hashCode: (PackageNode n) => n.name.hashCode,
+    ).expand((List<PackageNode> nodes) => nodes);
+    Future<BuildConfig> _packageBuildConfig(PackageNode package) async {
+      try {
+        return await BuildConfig.fromBuildConfigDir(package.name, package.dependencies.map((PackageNode node) => node.name), package.path);
+      } on ArgumentError catch (_) {
+        // During the build an error will be logged.
+        return BuildConfig.useDefault(package.name, package.dependencies.map((PackageNode node) => node.name));
+      }
+    }
+
+    final Iterable<BuildConfig> orderedConfigs = await Future.wait(orderedPackages.map(_packageBuildConfig));
+    final List<BuilderDefinition> builderDefinitions = orderedConfigs
+      .expand((BuildConfig buildConfig) => buildConfig.builderDefinitions.values)
+      .where((BuilderDefinition builderDefinition) {
+        if (builderDefinition.import.startsWith('package:')) {
+          return true;
+        }
+        return builderDefinition.package == packageGraph.root.name;
+      })
+      .toList();
+
+    final List<BuilderDefinition> orderedBuilders = _findBuilderOrder(builderDefinitions).toList();
+    builderApplications.addAll(orderedBuilders.map(_applyBuilder));
+
+    final List<PostProcessBuilderDefinition> postProcessBuilderDefinitions = orderedConfigs
+      .expand((BuildConfig buildConfig) => buildConfig.postProcessBuilderDefinitions.values)
+      .where((PostProcessBuilderDefinition builderDefinition) {
+        if (builderDefinition.import.startsWith('package:')) {
+          return true;
+        }
+        return builderDefinition.package == packageGraph.root.name;
+      })
+      .toList();
+    builderApplications.addAll(postProcessBuilderDefinitions.map(_applyPostProcessBuilder));
+
+    return builderApplications;
+  }
+
+  /// A method forwarding to `run`.
+  Method _createMain() {
+    return Method((MethodBuilder b) => b
+    ..name = 'main'
+    ..modifier = MethodModifier.async
+    ..requiredParameters.add(Parameter((ParameterBuilder parameterBuilder) => parameterBuilder
+      ..name = 'args'
+      ..type = TypeReference((TypeReferenceBuilder typeReferenceBuilder) => typeReferenceBuilder
+        ..symbol = 'List'
+        ..types.add(refer('String')))))
+    ..optionalParameters.add(Parameter((ParameterBuilder parameterBuilder) => parameterBuilder
+      ..name = 'sendPort'
+      ..type = refer('SendPort', 'dart:isolate')))
+    ..body = Block.of(<Code>[
+      refer('run', 'package:build_runner/build_runner.dart')
+          .call(<Expression>[refer('args'), refer('_builders')])
+          .awaited
+          .assignVar('result')
+          .statement,
+      refer('sendPort')
+          .nullSafeProperty('send')
+          .call(<Expression>[refer('result')]).statement,
+    ]));
+  }
+
+  /// An expression calling `apply` with appropriate setup for a Builder.
+  Expression _applyBuilder(BuilderDefinition definition) {
+    final Map<String, Expression> namedArgs = <String, Expression>{};
+    if (definition.isOptional) {
+      namedArgs['isOptional'] = literalTrue;
+    }
+    if (definition.buildTo == BuildTo.cache) {
+      namedArgs['hideOutput'] = literalTrue;
+    } else {
+      namedArgs['hideOutput'] = literalFalse;
+    }
+    if (!identical(definition.defaults?.generateFor, InputSet.anything)) {
+      final Map<String, Expression> inputSetArgs = <String, Expression>{};
+      if (definition.defaults.generateFor.include != null) {
+        inputSetArgs['include'] = literalConstList(definition.defaults.generateFor.include);
+      }
+      if (definition.defaults.generateFor.exclude != null) {
+        inputSetArgs['exclude'] = literalConstList(definition.defaults.generateFor.exclude);
+      }
+      namedArgs['defaultGenerateFor'] =
+          refer('InputSet', 'package:build_config/build_config.dart')
+              .constInstance(<Expression>[], inputSetArgs);
+    }
+    if (!identical(definition.defaults?.options, BuilderOptions.empty)) {
+      namedArgs['defaultOptions'] = _constructBuilderOptions(definition.defaults.options);
+    }
+    if (!identical(definition.defaults?.devOptions, BuilderOptions.empty)) {
+      namedArgs['defaultDevOptions'] = _constructBuilderOptions(definition.defaults.devOptions);
+    }
+    if (!identical(definition.defaults?.releaseOptions, BuilderOptions.empty)) {
+      namedArgs['defaultReleaseOptions'] = _constructBuilderOptions(definition.defaults.releaseOptions);
+    }
+    if (definition.appliesBuilders.isNotEmpty) {
+      namedArgs['appliesBuilders'] = literalList(definition.appliesBuilders);
+    }
+    final String import = _buildScriptImport(definition.import);
+    return refer('apply', 'package:build_runner_core/build_runner_core.dart')
+        .call(<Expression>[
+      literalString(definition.key),
+      literalList(
+          definition.builderFactories.map((String f) => refer(f, import)).toList()),
+      _findToExpression(definition),
+    ], namedArgs);
+  }
+
+  /// An expression calling `applyPostProcess` with appropriate setup for a
+  /// PostProcessBuilder.
+  Expression _applyPostProcessBuilder(PostProcessBuilderDefinition definition) {
+    final Map<String, Expression> namedArgs = <String, Expression>{};
+    if (definition.defaults?.generateFor != null) {
+      final Map<String, Expression> inputSetArgs = <String, Expression>{};
+      if (definition.defaults.generateFor.include != null) {
+        inputSetArgs['include'] = literalConstList(definition.defaults.generateFor.include);
+      }
+      if (definition.defaults.generateFor.exclude != null) {
+        inputSetArgs['exclude'] = literalConstList(definition.defaults.generateFor.exclude);
+      }
+      if (!identical(definition.defaults?.options, BuilderOptions.empty)) {
+        namedArgs['defaultOptions'] = _constructBuilderOptions(definition.defaults.options);
+      }
+      if (!identical(definition.defaults?.devOptions, BuilderOptions.empty)) {
+        namedArgs['defaultDevOptions'] = _constructBuilderOptions(definition.defaults.devOptions);
+      }
+      if (!identical(definition.defaults?.releaseOptions, BuilderOptions.empty)) {
+        namedArgs['defaultReleaseOptions'] = _constructBuilderOptions(definition.defaults.releaseOptions);
+      }
+      namedArgs['defaultGenerateFor'] = refer('InputSet', 'package:build_config/build_config.dart').constInstance(<Expression>[], inputSetArgs);
+    }
+    final String import = _buildScriptImport(definition.import);
+    return refer('applyPostProcess', 'package:build_runner_core/build_runner_core.dart')
+      .call(<Expression>[
+        literalString(definition.key),
+        refer(definition.builderFactory, import),
+      ], namedArgs);
+  }
+
+  /// Returns the actual import to put in the generated script based on an import
+  /// found in the build.yaml.
+  String _buildScriptImport(String import) {
+    if (import.startsWith('package:')) {
+      return import;
+    }
+    throwToolExit('non-package import syntax in build.yaml is not supported');
+    return null;
+  }
+
+  Expression _findToExpression(BuilderDefinition definition) {
+    switch (definition.autoApply) {
+      case AutoApply.none:
+        return refer('toNoneByDefault',
+                'package:build_runner_core/build_runner_core.dart')
+            .call(<Expression>[]);
+      case AutoApply.dependents:
+        return refer('toDependentsOf',
+                'package:build_runner_core/build_runner_core.dart')
+            .call(<Expression>[literalString(definition.package)]);
+      case AutoApply.allPackages:
+        return refer('toAllPackages',
+                'package:build_runner_core/build_runner_core.dart')
+            .call(<Expression>[]);
+      case AutoApply.rootPackage:
+        return refer('toRoot', 'package:build_runner_core/build_runner_core.dart')
+            .call(<Expression>[]);
+    }
+    throw ArgumentError('Unhandled AutoApply type: ${definition.autoApply}');
+  }
+
+  /// An expression creating a [BuilderOptions] from a json string.
+  Expression _constructBuilderOptions(BuilderOptions options) {
+    return refer('BuilderOptions', 'package:build/build.dart').newInstance(<Expression>[literalMap(options.config)]);
+  }
+
+  /// Put [builders] into an order such that any builder which specifies
+  /// [BuilderDefinition.requiredInputs] will come after any builder which
+  /// produces a desired output.
+  ///
+  /// Builders will be ordered such that their `required_inputs` and `runs_before`
+  /// constraints are met, but the rest of the ordering is arbitrary.
+  Iterable<BuilderDefinition> _findBuilderOrder(Iterable<BuilderDefinition> builders) {
+    Iterable<BuilderDefinition> dependencies(BuilderDefinition parent) {
+      return builders.where((BuilderDefinition child) => _hasInputDependency(parent, child) || _mustRunBefore(parent, child));
+    }
+    final List<List<BuilderDefinition>> components = stronglyConnectedComponents<BuilderDefinition>(
+      builders,
+      dependencies,
+      equals: (BuilderDefinition a, BuilderDefinition b) => a.key == b.key,
+      hashCode: (BuilderDefinition b) => b.key.hashCode,
+    );
+    return components.map((List<BuilderDefinition> component) {
+      if (component.length > 1) {
+        throw ArgumentError('Required input cycle for ${component.toList()}');
+      }
+      return component.single;
+    }).toList();
+  }
+
+  /// Whether [parent] has a `required_input` that wants to read outputs produced
+  /// by [child].
+  bool _hasInputDependency(BuilderDefinition parent, BuilderDefinition child) {
+    final Set<String> childOutputs = child.buildExtensions.values.expand((List<String> values) => values).toSet();
+    return parent.requiredInputs.any((String input) => childOutputs.any((String output) => output.endsWith(input)));
+  }
+
+  /// Whether [child] specifies that it wants to run before [parent].
+  bool _mustRunBefore(BuilderDefinition parent, BuilderDefinition child) => child.runsBefore.contains(parent.key);
+}
\ No newline at end of file
diff --git a/packages/flutter_tools/lib/src/commands/update_packages.dart b/packages/flutter_tools/lib/src/commands/update_packages.dart
index f1f9d3d8a15..07aab13a7e1 100644
--- a/packages/flutter_tools/lib/src/commands/update_packages.dart
+++ b/packages/flutter_tools/lib/src/commands/update_packages.dart
@@ -119,7 +119,7 @@ class UpdatePackagesCommand extends FlutterCommand {
         );
       }
       // Only retain flutter, flutter_test, flutter_driver, and flutter_localizations.
-      const List<String> consumerPackages = <String>['flutter', 'flutter_test', 'flutter_driver', 'flutter_localizations', 'flutter_build'];
+      const List<String> consumerPackages = <String>['flutter', 'flutter_test', 'flutter_driver', 'flutter_localizations'];
       // ensure we only get flutter/packages
       packages.retainWhere((Directory directory) {
         return consumerPackages.any((String package) {
diff --git a/packages/flutter_tools/lib/src/context_runner.dart b/packages/flutter_tools/lib/src/context_runner.dart
index deb0e228fc6..7229b9017d4 100644
--- a/packages/flutter_tools/lib/src/context_runner.dart
+++ b/packages/flutter_tools/lib/src/context_runner.dart
@@ -22,6 +22,7 @@ import 'base/time.dart';
 import 'base/user_messages.dart';
 import 'base/utils.dart';
 import 'build_runner/build_runner.dart';
+import 'build_runner/build_script_generator.dart';
 import 'cache.dart';
 import 'compile.dart';
 import 'devfs.dart';
@@ -60,6 +61,7 @@ Future<T> runInContext<T>(
       Artifacts: () => CachedArtifacts(),
       AssetBundleFactory: () => AssetBundleFactory.defaultInstance,
       BotDetector: () => const BotDetector(),
+      BuildScriptGeneratorFactory: () => const BuildScriptGeneratorFactory(),
       BuildRunnerFactory: () => const BuildRunnerFactory(),
       Cache: () => Cache(),
       CocoaPods: () => CocoaPods(),
diff --git a/packages/flutter_tools/lib/src/project.dart b/packages/flutter_tools/lib/src/project.dart
index bfbe689bd05..68f1f1228ca 100644
--- a/packages/flutter_tools/lib/src/project.dart
+++ b/packages/flutter_tools/lib/src/project.dart
@@ -4,7 +4,9 @@
 
 import 'dart:async';
 
+import 'package:build_runner_core/build_runner_core.dart';
 import 'package:meta/meta.dart';
+import 'package:yaml/yaml.dart';
 
 import 'android/gradle.dart' as gradle;
 import 'base/common.dart';
@@ -144,6 +146,23 @@ class FlutterProject {
     await ios.ensureReadyForPlatformSpecificTooling();
     await injectPlugins(this);
   }
+
+  /// Return the build_runner [PackageGraph] for this package.
+  Future<PackageGraph> get packageGraph async {
+    return PackageGraph.forPath(directory.path);
+  }
+
+  /// Return the set of builders used by this package.
+  Future<List<String>> get builders async {
+    final YamlMap pubspec = loadYaml(await pubspecFile.readAsString());
+    final YamlList builders = pubspec['builders'];
+    if (builders == null) {
+      return <String>[];
+    }
+    return builders.map<String>((Object node) {
+      return node.toString();
+    }).toList();
+  }
 }
 
 /// Represents the iOS sub-project of a Flutter project.
diff --git a/packages/flutter_tools/pubspec.yaml b/packages/flutter_tools/pubspec.yaml
index 25bc40fb216..5e2f0dbbbdd 100644
--- a/packages/flutter_tools/pubspec.yaml
+++ b/packages/flutter_tools/pubspec.yaml
@@ -23,7 +23,7 @@ dependencies:
   json_schema: 1.0.10
   linter: 0.1.74
   meta: 1.1.6
-  mustache: 1.1.0
+  mustache: 1.1.1
   package_config: 1.0.5
   platform: 2.2.0
   plugin: 0.2.0+3
@@ -39,23 +39,40 @@ dependencies:
   flutter_goldens_client:
     path: ../flutter_goldens_client
 
+  # build_runner depenencies needed for codegen.
+  build: 1.1.0
+  build_modules: 1.0.6
+
   # We depend on very specific internal implementation details of the
   # 'test' package, which change between versions, so when upgrading
   # this, make sure the tests are still running correctly.
   test_api: 0.2.2
-  test_core: 0.2.1
+  test_core: 0.2.1+1
+
+  # Code generation dependencies
+  build_runner_core: 2.0.1
+  dart_style: 1.2.0
+  code_builder: 3.2.0
 
   async: 2.0.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  bazel_worker: 0.1.18 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   boolean_selector: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  build_config: 0.3.1+4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  build_resolvers: 0.2.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  built_collection: 4.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  built_value: 6.3.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   charcode: 1.1.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   convert: 2.1.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   csslib: 0.14.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   dart2_constant: 1.0.2+dart2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  fixnum: 0.10.9 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   front_end: 0.1.6+9 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   glob: 1.1.7 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  graphs: 0.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   html: 0.13.3+3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   http_parser: 3.1.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   io: 0.3.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  json_annotation: 2.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   kernel: 0.3.6+9 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   logging: 0.11.3+2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   matcher: 0.12.3+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -64,12 +81,17 @@ dependencies:
   pedantic: 1.4.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   petitparser: 2.1.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   pool: 1.4.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  protobuf: 0.13.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   pub_semver: 1.4.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  pubspec_parse: 0.1.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  scratch_space: 0.0.3+2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   source_map_stack_trace: 1.1.5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   source_maps: 0.10.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   source_span: 1.5.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  stream_transform: 0.0.14+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   string_scanner: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   term_glyph: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  timing: 0.1.1+1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   typed_data: 1.1.6 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   utf: 0.9.0+5 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   watcher: 0.9.7+10 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -89,10 +111,10 @@ dev_dependencies:
   shelf_packages_handler: 1.0.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   shelf_static: 0.2.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   shelf_web_socket: 0.2.2+4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  test: 1.5.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test: 1.5.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
 
 dartdoc:
   # Exclude this package from the hosted API docs.
   nodoc: true
 
-# PUBSPEC CHECKSUM: 8bcf
+# PUBSPEC CHECKSUM: 7930
diff --git a/packages/flutter_tools/test/build_runner/build_runner_test.dart b/packages/flutter_tools/test/build_runner/build_runner_test.dart
index 289adbd1cc0..a69ee5f3c51 100644
--- a/packages/flutter_tools/test/build_runner/build_runner_test.dart
+++ b/packages/flutter_tools/test/build_runner/build_runner_test.dart
@@ -2,103 +2,35 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:convert';
 
-import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/platform.dart';
 import 'package:flutter_tools/src/build_runner/build_runner.dart';
 import 'package:mockito/mockito.dart';
-import 'package:process/process.dart';
 
 import '../src/common.dart';
 import '../src/context.dart';
 
 void main() {
   group('experimentalBuildEnabled', () {
-    final MockProcessManager mockProcessManager = MockProcessManager();
     final MockPlatform mockPlatform = MockPlatform();
-    final MockFileSystem mockFileSystem = MockFileSystem();
 
     setUp(() {
       experimentalBuildEnabled = null;
     });
-    testUsingContext('is enabled if environment variable is enabled and project '
-      'contains a dependency on flutter_build and build_runner', () async {
-        final MockDirectory projectDirectory = MockDirectory();
-        final MockDirectory exampleDirectory = MockDirectory();
-        final MockFile packagesFile = MockFile();
-        final MockFile pubspecFile = MockFile();
-        final MockFile examplePubspecFile = MockFile();
-        const String packages = r'''
-flutter_build:file:///Users/tester/.pub-cache/hosted/pub.dartlang.org/flutter_build/lib/
-build_runner:file:///Users/tester/.pub-cache/hosted/pub.dartlang.org/build_runner/lib/
-example:lib/
-''';
-        when(mockPlatform.environment).thenReturn(<String, String>{'FLUTTER_EXPERIMENTAL_BUILD': 'true'});
-        when(mockFileSystem.currentDirectory).thenReturn(projectDirectory);
-        when(mockFileSystem.isFileSync(any)).thenReturn(false);
-        when(projectDirectory.childFile('pubspec.yaml')).thenReturn(pubspecFile);
-        when(projectDirectory.childFile('.packages')).thenReturn(packagesFile);
-        when(projectDirectory.childDirectory('example')).thenReturn(exampleDirectory);
-        when(exampleDirectory.childFile('pubspec.yaml')).thenReturn(examplePubspecFile);
-        when(packagesFile.path).thenReturn('/test/.packages');
-        when(pubspecFile.path).thenReturn('/test/pubspec.yaml');
-        when(examplePubspecFile.path).thenReturn('/test/example/pubspec.yaml');
-        when(mockFileSystem.file('/test/.packages')).thenReturn(packagesFile);
-        when(packagesFile.readAsBytesSync()).thenReturn(utf8.encode(packages));
-
-        expect(await experimentalBuildEnabled, true);
+    testUsingContext('is enabled if environment variable is enabled', () async {
+      when(mockPlatform.environment).thenReturn(<String, String>{'FLUTTER_EXPERIMENTAL_BUILD': 'true'});
+      expect(experimentalBuildEnabled, true);
     }, overrides: <Type, Generator>{
-      ProcessManager: () => mockProcessManager,
       Platform: () => mockPlatform,
-      FileSystem: () => mockFileSystem,
     });
 
-    testUsingContext('is not enabled if environment variable is enabled and project '
-      'does not contain a dependency on flutter_build', () async {
-        final MockDirectory projectDirectory = MockDirectory();
-        final MockDirectory exampleDirectory = MockDirectory();
-        final MockFile packagesFile = MockFile();
-        final MockFile pubspecFile = MockFile();
-        final MockFile examplePubspecFile = MockFile();
-        const String packages = r'''
-build_runner:file:///Users/tester/.pub-cache/hosted/pub.dartlang.org/build_runner/lib/
-example:lib/
-''';
-        when(mockPlatform.environment).thenReturn(<String, String>{'FLUTTER_EXPERIMENTAL_BUILD': 'true'});
-        when(mockFileSystem.currentDirectory).thenReturn(projectDirectory);
-        when(mockFileSystem.isFileSync(any)).thenReturn(false);
-        when(projectDirectory.childFile('pubspec.yaml')).thenReturn(pubspecFile);
-        when(projectDirectory.childFile('.packages')).thenReturn(packagesFile);
-        when(projectDirectory.childDirectory('example')).thenReturn(exampleDirectory);
-        when(exampleDirectory.childFile('pubspec.yaml')).thenReturn(examplePubspecFile);
-        when(packagesFile.path).thenReturn('/test/.packages');
-        when(pubspecFile.path).thenReturn('/test/pubspec.yaml');
-        when(examplePubspecFile.path).thenReturn('/test/example/pubspec.yaml');
-        when(mockFileSystem.file('/test/.packages')).thenReturn(packagesFile);
-        when(packagesFile.readAsBytesSync()).thenReturn(utf8.encode(packages));
-
-        expect(await experimentalBuildEnabled, false);
-    }, overrides: <Type, Generator>{
-      ProcessManager: () => mockProcessManager,
-      Platform: () => mockPlatform,
-      FileSystem: () => mockFileSystem,
-    });
-
-
     testUsingContext('is not enabed if environment varable is not enabled', () async {
       when(mockPlatform.environment).thenReturn(<String, String>{});
-      expect(await experimentalBuildEnabled, false);
+      expect(experimentalBuildEnabled, false);
     }, overrides: <Type, Generator>{
-      ProcessManager: () => mockProcessManager,
       Platform: () => mockPlatform,
-      FileSystem: () => mockFileSystem,
     });
   });
 }
 
-class MockProcessManager extends Mock implements ProcessManager {}
-class MockPlatform extends Mock implements Platform {}
-class MockFileSystem extends Mock implements FileSystem {}
-class MockDirectory extends Mock implements Directory {}
-class MockFile extends Mock implements File {}
+class MockPlatform extends Mock implements Platform {}
\ No newline at end of file
diff --git a/packages/flutter_tools/test/forbidden_imports_test.dart b/packages/flutter_tools/test/forbidden_imports_test.dart
index 06b1fc6ff7a..3b3c3c2e239 100644
--- a/packages/flutter_tools/test/forbidden_imports_test.dart
+++ b/packages/flutter_tools/test/forbidden_imports_test.dart
@@ -10,8 +10,11 @@ void main() {
   final String flutterTools = fs.path.join(getFlutterRoot(), 'packages', 'flutter_tools');
 
   test('no unauthorized imports of dart:io', () {
-    final String whitelistedPath = fs.path.join(flutterTools, 'lib', 'src', 'base', 'io.dart');
-    bool _isNotWhitelisted(FileSystemEntity entity) => entity.path != whitelistedPath;
+    final List<String> whitelistedPaths = <String>[
+      fs.path.join(flutterTools, 'lib', 'src', 'base', 'io.dart'),
+      fs.path.join(flutterTools, 'lib', 'src', 'build_runner', 'kernel_builder.dart'),
+    ];
+    bool _isNotWhitelisted(FileSystemEntity entity) => whitelistedPaths.every((String path) => path != entity.path);
 
     for (String dirName in <String>['lib', 'bin']) {
       final Iterable<File> files = fs.directory(fs.path.join(flutterTools, dirName))
@@ -32,14 +35,17 @@ void main() {
   });
 
   test('no unauthorized imports of package:path', () {
+    final String whitelistedPath = fs.path.join(flutterTools, 'lib', 'src', 'build_runner', 'kernel_builder.dart');
     for (String dirName in <String>['lib', 'bin', 'test']) {
       final Iterable<File> files = fs.directory(fs.path.join(flutterTools, dirName))
         .listSync(recursive: true)
         .where(_isDartFile)
+        .where((FileSystemEntity entity) => entity.path != whitelistedPath)
         .map(_asFile);
       for (File file in files) {
         for (String line in file.readAsLinesSync()) {
-          if (line.startsWith(RegExp(r'import.*package:path/path.dart'))) {
+          if (line.startsWith(RegExp(r'import.*package:path/path.dart')) &&
+              !line.contains('ignore: package_path_import')) {
             final String relativePath = fs.path.relative(file.path, from:flutterTools);
             fail("$relativePath imports 'package:path/path.dart'; use 'fs.path' instead");
           }
@@ -49,8 +55,11 @@ void main() {
   });
 
   test('no unauthorized imports of dart:convert', () {
-    final String whitelistedPath = fs.path.join(flutterTools, 'lib', 'src', 'convert.dart');
-    bool _isNotWhitelisted(FileSystemEntity entity) => entity.path != whitelistedPath;
+    final List<String> whitelistedPaths = <String>[
+      fs.path.join(flutterTools, 'lib', 'src', 'convert.dart'),
+      fs.path.join(flutterTools, 'lib', 'src', 'build_runner', 'kernel_builder.dart'),
+    ];
+    bool _isNotWhitelisted(FileSystemEntity entity) => whitelistedPaths.every((String path) => path != entity.path);
 
     for (String dirName in <String>['lib']) {
       final Iterable<File> files = fs.directory(fs.path.join(flutterTools, dirName))