Handle failures in the bot_update script.

Currently, if the bot_update script fails, then recipe code that makes
assumptions about the returned output JSON cause exceptions to be
raised. This fixes a couple instances in the code so that the bot_update
failure should surface instead of an uncaught exception.

Change-Id: I031e613841b03e5eb4f6d9ca7adb5085088a3077
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2405708
Auto-Submit: Garrett Beaty <gbeaty@chromium.org>
Reviewed-by: Josip Sokcevic <sokcevic@google.com>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>

recipes/README.recipes.md

@@ -58,7 +58,7 @@ Recipe module to ensure a checkout is consistent on a bot.
 
 Wrapper for easy calling of bot_update.
 
-— **def [deapply\_patch](/recipes/recipe_modules/bot_update/api.py#518)(self, bot_update_step):**
+— **def [deapply\_patch](/recipes/recipe_modules/bot_update/api.py#519)(self, bot_update_step):**
 
 Deapplies a patch, taking care of DEPS and solution revisions properly.
     
@@ -89,7 +89,7 @@ Args:
   step_test_data: a null function that returns test bot_update.py output.
     Use test_api.output_json to generate test data.
 
-— **def [get\_project\_revision\_properties](/recipes/recipe_modules/bot_update/api.py#495)(self, project_name, gclient_config=None):**
+— **def [get\_project\_revision\_properties](/recipes/recipe_modules/bot_update/api.py#496)(self, project_name, gclient_config=None):**
 
 Returns all property names used for storing the checked-out revision of
 a given project.
@@ -107,7 +107,7 @@ Returns (list of str): All properties that'll hold the checked-out revision
 
 &emsp; **@property**<br>&mdash; **def [last\_returned\_properties](/recipes/recipe_modules/bot_update/api.py#44)(self):**
 
-&mdash; **def [resolve\_fixed\_revision](/recipes/recipe_modules/bot_update/api.py#445)(self, bot_update_json, name):**
+&mdash; **def [resolve\_fixed\_revision](/recipes/recipe_modules/bot_update/api.py#446)(self, bot_update_json, name):**
 
 Set a fixed revision for a single dependency using project revision
 properties.

recipes/recipe_modules/bot_update/api.py

@@ -320,7 +320,7 @@ class BotUpdateApi(recipe_api.RecipeApi):
           step_text = result['step_text']
           step_result.presentation.step_text = step_text
 
-        if add_blamelists:
+        if add_blamelists and 'manifest' in result:
           blamelist_pins = []
           for name in revisions:
             m = result['manifest'][name]
@@ -333,7 +333,8 @@ class BotUpdateApi(recipe_api.RecipeApi):
           self.m.milo.show_blamelist_for(blamelist_pins)
 
         # Set output commit of the build.
-        if set_output_commit:
+        if (set_output_commit and
+            'got_revision' in self._last_returned_properties):
           # As of April 2019, got_revision describes the output commit,
           # the same commit that Build.output.gitiles_commit describes.
           # In particular, users tend to set got_revision to make Milo display

recipes/recipe_modules/bot_update/examples/full.expected/add_blamelists_bot_update_failure.json

+[
+  {
+    "cmd": [
+      "python",
+      "-u",
+      "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
+      "--spec-path",
+      "cache_dir = '[CACHE]/git'\nsolutions = [{'deps_file': '.DEPS.git', 'managed': True, 'name': 'src', 'url': 'https://chromium.googlesource.com/chromium/src.git'}]",
+      "--revision_mapping_file",
+      "{\"got_angle_revision\": \"src/third_party/angle\", \"got_cr_revision\": \"src\", \"got_revision\": \"src\", \"got_v8_revision\": \"src/v8\"}",
+      "--git-cache-dir",
+      "[CACHE]/git",
+      "--cleanup-dir",
+      "[CLEANUP]/bot_update",
+      "--output_json",
+      "/path/to/tmp/json",
+      "--revision",
+      "src@2d72510e447ab60a9728aeea2362d8be2cbd7789",
+      "--revision",
+      "src/v8@HEAD",
+      "--refs",
+      "refs/heads/master",
+      "--disable-syntax-validation"
+    ],
+    "env": {
+      "GIT_HTTP_LOW_SPEED_LIMIT": "102400",
+      "GIT_HTTP_LOW_SPEED_TIME": "300"
+    },
+    "env_suffixes": {
+      "DEPOT_TOOLS_UPDATE": [
+        "0"
+      ],
+      "PATH": [
+        "RECIPE_REPO[depot_tools]"
+      ]
+    },
+    "infra_step": true,
+    "name": "bot_update (without patch)",
+    "~followup_annotations": [
+      "@@@STEP_LOG_LINE@json.output@{@@@",
+      "@@@STEP_LOG_LINE@json.output@  \"did_run\": true@@@",
+      "@@@STEP_LOG_LINE@json.output@}@@@",
+      "@@@STEP_LOG_END@json.output@@@"
+    ]
+  },
+  {
+    "name": "$result"
+  }
+]
\ No newline at end of file

recipes/recipe_modules/bot_update/examples/full.expected/bot_update_failure.json

+[
+  {
+    "cmd": [
+      "python",
+      "-u",
+      "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
+      "--spec-path",
+      "cache_dir = '[CACHE]/git'\nsolutions = [{'deps_file': '.DEPS.git', 'managed': True, 'name': 'src', 'url': 'https://chromium.googlesource.com/chromium/src.git'}]",
+      "--revision_mapping_file",
+      "{\"got_angle_revision\": \"src/third_party/angle\", \"got_cr_revision\": \"src\", \"got_revision\": \"src\", \"got_v8_revision\": \"src/v8\"}",
+      "--git-cache-dir",
+      "[CACHE]/git",
+      "--cleanup-dir",
+      "[CLEANUP]/bot_update",
+      "--output_json",
+      "/path/to/tmp/json",
+      "--revision",
+      "src@2d72510e447ab60a9728aeea2362d8be2cbd7789",
+      "--refs",
+      "refs/heads/master",
+      "--disable-syntax-validation"
+    ],
+    "env": {
+      "GIT_HTTP_LOW_SPEED_LIMIT": "102400",
+      "GIT_HTTP_LOW_SPEED_TIME": "300"
+    },
+    "env_suffixes": {
+      "DEPOT_TOOLS_UPDATE": [
+        "0"
+      ],
+      "PATH": [
+        "RECIPE_REPO[depot_tools]"
+      ]
+    },
+    "infra_step": true,
+    "name": "bot_update (without patch)",
+    "~followup_annotations": [
+      "@@@STEP_LOG_LINE@json.output@{@@@",
+      "@@@STEP_LOG_LINE@json.output@  \"did_run\": true@@@",
+      "@@@STEP_LOG_LINE@json.output@}@@@",
+      "@@@STEP_LOG_END@json.output@@@"
+    ]
+  },
+  {
+    "name": "$result"
+  }
+]
\ No newline at end of file

recipes/recipe_modules/bot_update/examples/full.py

@@ -119,6 +119,12 @@ def GenTests(api):
       api.test('unrecognized_commit_repo') +
       ci_build(git_repo='https://unrecognized/repo')
   )
+  yield (
+      api.test('bot_update_failure') +
+      ci_build() +
+      api.properties(bot_update_output={'did_run': True})
+  )
+
   yield (
       api.test('basic_luci') +
       ci_build() +
@@ -246,6 +252,16 @@ def GenTests(api):
       )
   )
 
+  yield (
+      api.test('add_blamelists_bot_update_failure') +
+      ci_build() +
+      api.properties(
+          add_blamelists=True,
+          bot_update_output={'did_run': True},
+          revisions={'src/v8': 'HEAD'},
+      )
+  )
+
   yield (
       api.test('no_cp_checkout_a_specific_commit') +
       ci_build(revision='a' * 40) +