Version 2.12.0-250.0.dev

Merge commit '9fa2a462c5725355a10d0da9976e80b37693246b' into 'dev'
diff --git a/.dart_tool/package_config.json b/.dart_tool/package_config.json
index dfab19e..ff74a21 100644
--- a/.dart_tool/package_config.json
+++ b/.dart_tool/package_config.json
@@ -472,7 +472,7 @@
       "name": "package_config",
       "rootUri": "../third_party/pkg_tested/package_config",
       "packageUri": "lib/",
-      "languageVersion": "2.7"
+      "languageVersion": "2.12"
     },
     {
       "name": "package_deps",
diff --git a/DEPS b/DEPS
index 87fb107..f591082 100644
--- a/DEPS
+++ b/DEPS
@@ -127,7 +127,7 @@
   "mockito_rev": "d39ac507483b9891165e422ec98d9fb480037c8b",
   "mustache_rev": "664737ecad027e6b96d0d1e627257efa0e46fcb1",
   "oauth2_tag": "1.6.0",
-  "package_config_rev": "9c586d04bd26fef01215fd10e7ab96a3050cfa64",
+  "package_config_rev": "0e208cb5a9482d780c47627368d3f5bdc409f37b",
   "path_rev": "62ecd5a78ffe5734d14ed0df76d20309084cd04a",
   "pedantic_rev": "a884ea2db943b8756cc94385990bd750aec06928",
   "ply_rev": "604b32590ffad5cbb82e4afef1d305512d06ae93",
diff --git a/tools/VERSION b/tools/VERSION
index fc35def..b96128e 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -27,5 +27,5 @@
 MAJOR 2
 MINOR 12
 PATCH 0
-PRERELEASE 249
+PRERELEASE 250
 PRERELEASE_PATCH 0
\ No newline at end of file