Auto merge of #24811 - servo:fail-fast, r=jdmhomu-tmp

Fix updating the GitHub Status as soon as any TC task fails

… rather than only when the entire task group is resolved. This allows Homu to more quickly be notified of a failure, and move on to the next PR in the queue sooner.

(Plus drive-by Brewfile fix.)

8 files changed, 154 insertions, 93 deletions

diff --git a/.taskcluster.yml b/.taskcluster.yml
index d7b380ae766..b2c277f6f09 100644
--- a/.taskcluster.yml
+++ b/.taskcluster.yml
@@ -1,4 +1,8 @@
 version: 1
+
+# If and when switching to `reporting: checks-v1` here, also change the `statuses` route to `checks`
+# in `CONFIG.routes_for_all_subtasks` in `etc/taskcluster/decision_task.py`
+
 policy:
   # https://docs.taskcluster.net/docs/reference/integrations/taskcluster-github/docs/taskcluster-yml-v1#pull-requests
   pullRequests: public
@@ -27,6 +31,11 @@ tasks:
             sha256:7471a998e4462638c8d3e2cf0b4a99c9a5c8ca9f2ec0ae01cc069473b35cde10"
         features:
           taskclusterProxy: true
+        artifacts:
+          public/repo.bundle:
+            type: file
+            path: /repo.bundle
+            expires: {$fromNow: '1 day'}
         env:
           GIT_URL: ${event.repository.clone_url}
           TASK_FOR: ${tasks_for}
diff --git a/etc/taskcluster/decision_task.py b/etc/taskcluster/decision_task.py
index efebbaec2dc..9342e658830 100644
--- a/etc/taskcluster/decision_task.py
+++ b/etc/taskcluster/decision_task.py
@@ -10,12 +10,23 @@ from decisionlib import CONFIG, SHARED
 
 
 def main(task_for):
+    with decisionlib.make_repo_bundle():
+        tasks(task_for)
+
+
+def tasks(task_for):
     if CONFIG.git_ref.startswith("refs/heads/"):
         branch = CONFIG.git_ref[len("refs/heads/"):]
         CONFIG.treeherder_repository_name = "servo-" + (
             branch if not branch.startswith("try-") else "try"
         )
 
+    # Work around a tc-github bug/limitation:
+    # https://bugzilla.mozilla.org/show_bug.cgi?id=1548781#c4
+    if task_for.startswith("github"):
+        # https://github.com/taskcluster/taskcluster/blob/21f257dc8/services/github/config.yml#L14
+        CONFIG.routes_for_all_subtasks.append("statuses")
+
     # The magicleap build is broken until there's a surfman back end
     magicleap_dev = lambda: None
     magicleap_nightly = lambda: None
@@ -166,7 +177,7 @@ def linux_tidy_unit_untrusted():
         .with_max_run_time_minutes(60)
         .with_dockerfile(dockerfile_path("build"))
         .with_env(**build_env, **unix_build_env, **linux_build_env)
-        .with_repo()
+        .with_repo_bundle()
         .with_script("rustup set profile minimal")
         # required by components/script_plugins:
         .with_script("rustup component add rustc-dev")
@@ -378,7 +389,7 @@ def android_x86_release():
 
 def android_x86_wpt():
     build_task = android_x86_release()
-    return (
+    task = (
         linux_task("WPT")
         .with_treeherder("Android x86")
         .with_provisioner_id("proj-servo")
@@ -386,8 +397,13 @@ def android_x86_wpt():
         .with_capabilities(privileged=True)
         .with_scopes("project:servo:docker-worker-kvm:capability:privileged")
         .with_dockerfile(dockerfile_path("run-android-emulator"))
-        .with_repo()
-        .with_curl_artifact_script(build_task, "servoapp.apk", "target/android/i686-linux-android/release")
+        .with_repo_bundle()
+    )
+    apk_dir = "target/android/i686-linux-android/release"
+    return (
+        task
+        .with_script("mkdir -p " + apk_dir)
+        .with_curl_artifact_script(build_task, "servoapp.apk", apk_dir)
         .with_script("""
             ./mach bootstrap-android --accept-all-licences --emulator-x86
             ./mach test-android-startup --release
@@ -551,7 +567,7 @@ def linux_wpt():
         .find_or_create("build.linux_x64_release_w_assertions" + CONFIG.task_id())
     )
     def linux_run_task(name):
-        return linux_task(name).with_dockerfile(dockerfile_path("run"))
+        return linux_task(name).with_dockerfile(dockerfile_path("run")).with_repo_bundle()
     wpt_chunks("Linux x64", linux_run_task, release_build_task, repo_dir="/repo",
                total_chunks=4, processes=12)
 
@@ -585,14 +601,14 @@ def update_wpt():
         .with_scopes("secrets:get:project/servo/wpt-sync")
         .with_index_and_artifacts_expire_in(log_artifacts_expire_in)
         .with_max_run_time_minutes(6 * 60)
+        # Not using the bundle, pushing the new changes to the git remote requires a full repo.
+        .with_repo(alternate_object_dir="/var/cache/servo.git/objects")
     )
     return (
         with_homebrew(update_task, [
-            "etc/taskcluster/macos/Brewfile-wpt",
-            "etc/taskcluster/macos/Brewfile-gstreamer",
+            "etc/taskcluster/macos/Brewfile-wpt-update",
+            "etc/taskcluster/macos/Brewfile",
         ])
-        # Pushing the new changes to the git remote requires a full repo clone.
-        .with_repo(shallow=False, alternate_object_dir="/var/cache/servo.git/objects")
         .with_curl_artifact_script(build_task, "target.tar.gz")
         .with_script("""
             export PKG_CONFIG_PATH="$(brew --prefix libffi)/lib/pkgconfig/"
@@ -628,21 +644,21 @@ def macos_wpt():
     priority = "high" if CONFIG.git_ref == "refs/heads/auto" else None
     build_task = macos_release_build_with_debug_assertions(priority=priority)
     def macos_run_task(name):
-        task = macos_task(name).with_python2()
-        return with_homebrew(task, ["etc/taskcluster/macos/Brewfile-gstreamer"])
+        task = macos_task(name).with_python2() \
+            .with_repo_bundle(alternate_object_dir="/var/cache/servo.git/objects")
+        return with_homebrew(task, ["etc/taskcluster/macos/Brewfile"])
     wpt_chunks(
         "macOS x64",
         macos_run_task,
         build_task,
         repo_dir="repo",
-        repo_kwargs=dict(alternate_object_dir="/var/cache/servo.git/objects"),
         total_chunks=30,
         processes=4,
     )
 
 
 def wpt_chunks(platform, make_chunk_task, build_task, total_chunks, processes,
-               repo_dir, chunks="all", repo_kwargs={}):
+               repo_dir, chunks="all"):
     if chunks == "all":
         chunks = range(total_chunks + 1)
     for this_chunk in chunks:
@@ -651,7 +667,6 @@ def wpt_chunks(platform, make_chunk_task, build_task, total_chunks, processes,
                 this_chunk, total_chunks, width=len(str(total_chunks)),
             ))
             .with_treeherder(platform, "WPT-%s" % this_chunk)
-            .with_repo(**repo_kwargs)
             .with_curl_artifact_script(build_task, "target.tar.gz")
             .with_script("tar -xzf target.tar.gz")
             .with_index_and_artifacts_expire_in(log_artifacts_expire_in)
@@ -798,7 +813,7 @@ def linux_build_task(name, *, build_env=build_env, install_rustc_dev=True):
         .with_max_run_time_minutes(60)
         .with_dockerfile(dockerfile_path("build"))
         .with_env(**build_env, **unix_build_env, **linux_build_env)
-        .with_repo()
+        .with_repo_bundle()
         .with_script("rustup set profile minimal")
     )
     if install_rustc_dev:
@@ -841,7 +856,7 @@ def windows_build_task(name, package=True, arch="x86_64"):
             **windows_build_env[arch],
             **windows_build_env["all"]
         )
-        .with_repo(sparse_checkout=windows_sparse_checkout)
+        .with_repo_bundle(sparse_checkout=windows_sparse_checkout)
         .with_python2()
         .with_directory_mount(
             "https://www.python.org/ftp/python/3.7.3/python-3.7.3-embed-amd64.zip",
@@ -894,7 +909,7 @@ def macos_build_task(name):
         # https://github.com/servo/servo/issues/24735
         .with_max_run_time_minutes(60 * 2)
         .with_env(**build_env, **unix_build_env, **macos_build_env)
-        .with_repo(alternate_object_dir="/var/cache/servo.git/objects")
+        .with_repo_bundle(alternate_object_dir="/var/cache/servo.git/objects")
         .with_python2()
         .with_rustup()
         # Since macOS workers are long-lived and ~/.rustup kept across tasks:
@@ -910,7 +925,7 @@ def macos_build_task(name):
     return (
         with_homebrew(build_task, [
             "etc/taskcluster/macos/Brewfile",
-            "etc/taskcluster/macos/Brewfile-gstreamer",
+            "etc/taskcluster/macos/Brewfile-build",
         ])
         .with_script("""
             export OPENSSL_INCLUDE_DIR="$(brew --prefix openssl)/include"
diff --git a/etc/taskcluster/decisionlib.py b/etc/taskcluster/decisionlib.py
index acd8556ad79..ef585657a32 100644
--- a/etc/taskcluster/decisionlib.py
+++ b/etc/taskcluster/decisionlib.py
@@ -14,6 +14,7 @@ Project-independent library for Taskcluster decision tasks
 """
 
 import base64
+import contextlib
 import datetime
 import hashlib
 import json
@@ -28,6 +29,7 @@ import taskcluster
 __all__ = [
     "CONFIG", "SHARED", "Task", "DockerWorkerTask",
     "GenericWorkerTask", "WindowsGenericWorkerTask", "MacOsGenericWorkerTask",
+    "make_repo_bundle",
 ]
 
 
@@ -56,6 +58,7 @@ class Config:
         self.git_url = os.environ.get("GIT_URL")
         self.git_ref = os.environ.get("GIT_REF")
         self.git_sha = os.environ.get("GIT_SHA")
+        self.git_bundle_shallow_ref = "refs/heads/shallow"
 
         self.tc_root_url = os.environ.get("TASKCLUSTER_ROOT_URL")
         self.default_provisioner_id = "proj-example"
@@ -145,6 +148,9 @@ class Task:
         self.extra = {}
         self.treeherder_required = False
         self.priority = None  # Defaults to 'lowest'
+        self.git_fetch_url = CONFIG.git_url
+        self.git_fetch_ref = CONFIG.git_ref
+        self.git_checkout_sha = CONFIG.git_sha
 
     # All `with_*` methods return `self`, so multiple method calls can be chained.
     with_description = chaining(setattr, "description")
@@ -221,9 +227,14 @@ class Task:
         assert CONFIG.decision_task_id
         assert CONFIG.task_owner
         assert CONFIG.task_source
+
+        def dedup(xs):
+            seen = set()
+            return [x for x in xs if not (x in seen or seen.add(x))]
+
         queue_payload = {
             "taskGroupId": CONFIG.decision_task_id,
-            "dependencies": [CONFIG.decision_task_id] + self.dependencies,
+            "dependencies": dedup([CONFIG.decision_task_id] + self.dependencies),
             "schedulerId": self.scheduler_id,
             "provisionerId": self.provisioner_id,
             "workerType": self.worker_type,
@@ -299,6 +310,29 @@ class Task:
         SHARED.found_or_created_indexed_tasks[index_path] = task_id
         return task_id
 
+    def with_curl_script(self, url, file_path):
+        return self \
+        .with_script("""
+            curl --retry 5 --connect-timeout 10 -Lf "%s" -o "%s"
+        """ % (url, file_path))
+
+    def with_curl_artifact_script(self, task_id, artifact_name, out_directory=""):
+        queue_service = CONFIG.tc_root_url + "/api/queue"
+        return self \
+        .with_dependencies(task_id) \
+        .with_curl_script(
+            queue_service + "/v1/task/%s/artifacts/public/%s" % (task_id, artifact_name),
+            os.path.join(out_directory, url_basename(artifact_name)),
+        )
+
+    def with_repo_bundle(self, **kwargs):
+        self.git_fetch_url = "../repo.bundle"
+        self.git_fetch_ref = CONFIG.git_bundle_shallow_ref
+        self.git_checkout_sha = "FETCH_HEAD"
+        return self \
+        .with_curl_artifact_script(CONFIG.decision_task_id, "repo.bundle") \
+        .with_repo(**kwargs)
+
 
 class GenericWorkerTask(Task):
     """
@@ -453,9 +487,9 @@ class WindowsGenericWorkerTask(GenericWorkerTask):
             self.with_early_script("set PATH=%HOMEDRIVE%%HOMEPATH%\\{};%PATH%".format(p))
         return self
 
-    def with_repo(self, sparse_checkout=None, shallow=True):
+    def with_repo(self, sparse_checkout=None):
         """
-        Make a shallow clone the git repository at the start of the task.
+        Make a clone the git repository at the start of the task.
         This uses `CONFIG.git_url`, `CONFIG.git_ref`, and `CONFIG.git_sha`,
         and creates the clone in a `repo` directory in the task’s home directory.
 
@@ -478,13 +512,16 @@ class WindowsGenericWorkerTask(GenericWorkerTask):
                 type .git\\info\\sparse-checkout
             """
         git += """
-            git fetch --no-tags {depth} %GIT_URL% %GIT_REF%
-            git reset --hard %GIT_SHA%
-        """.format(depth="--depth 30" if shallow else "")
+            git fetch --no-tags {} {}
+            git reset --hard {}
+        """.format(
+            assert_truthy(self.git_fetch_url),
+            assert_truthy(self.git_fetch_ref),
+            assert_truthy(self.git_checkout_sha),
+        )
         return self \
         .with_git() \
-        .with_script(git) \
-        .with_env(**git_env())
+        .with_script(git)
 
     def with_git(self):
         """
@@ -501,6 +538,19 @@ class WindowsGenericWorkerTask(GenericWorkerTask):
             path="git",
         )
 
+    def with_curl_script(self, url, file_path):
+        self.with_curl()
+        return super().with_curl_script(url, file_path)
+
+    def with_curl(self):
+        return self \
+        .with_path_from_homedir("curl\\curl-7.67.0-win64-mingw\\bin") \
+        .with_directory_mount(
+            "https://curl.haxx.se/windows/dl-7.67.0_4/curl-7.67.0_4-win64-mingw.zip",
+            sha256="1d50deeac7f945ed75149e6300f6d21f007a6b942ab851a119ed76cdef27d714",
+            path="curl",
+        )
+
     def with_rustup(self):
         """
         Download rustup.rs and make it available to task commands,
@@ -578,13 +628,9 @@ class WindowsGenericWorkerTask(GenericWorkerTask):
 
 
 class UnixTaskMixin(Task):
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-        self.curl_scripts_count = 0
-
-    def with_repo(self, shallow=True, alternate_object_dir=None):
+    def with_repo(self, alternate_object_dir=""):
         """
-        Make a shallow clone the git repository at the start of the task.
+        Make a clone the git repository at the start of the task.
         This uses `CONFIG.git_url`, `CONFIG.git_ref`, and `CONFIG.git_sha`
 
         * generic-worker: creates the clone in a `repo` directory
@@ -597,46 +643,20 @@ class UnixTaskMixin(Task):
         """
         # Not using $GIT_ALTERNATE_OBJECT_DIRECTORIES since it causes
         # "object not found - no match for id" errors when Cargo fetches git dependencies
-        if alternate_object_dir:
-            self.with_env(ALTERNATE_OBJDIR=alternate_object_dir)
         return self \
-        .with_env(**git_env()) \
-        .with_early_script("""
+        .with_script("""
             git init repo
             cd repo
-            {alternate}
-            time git fetch --no-tags {depth} "$GIT_URL" "$GIT_REF"
-            time git reset --hard "$GIT_SHA"
+            echo "{alternate}" > .git/objects/info/alternates
+            time git fetch --no-tags {} {}
+            time git reset --hard {}
         """.format(
-            depth="--depth 30" if shallow else "",
-            alternate=(
-                """echo "$ALTERNATE_OBJDIR" > .git/objects/info/alternates"""
-                if alternate_object_dir else ""
-            )
+            assert_truthy(self.git_fetch_url),
+            assert_truthy(self.git_fetch_ref),
+            assert_truthy(self.git_checkout_sha),
+            alternate=alternate_object_dir,
         ))
 
-    def with_curl_script(self, url, file_path):
-        self.curl_scripts_count += 1
-        n = self.curl_scripts_count
-        return self \
-        .with_env(**{
-            "CURL_%s_URL" % n: url,
-            "CURL_%s_PATH" % n: file_path,
-        }) \
-        .with_script("""
-            mkdir -p $(dirname "$CURL_{n}_PATH")
-            curl --retry 5 --connect-timeout 10 -Lf "$CURL_{n}_URL" -o "$CURL_{n}_PATH"
-        """.format(n=n))
-
-    def with_curl_artifact_script(self, task_id, artifact_name, out_directory=""):
-        queue_service = CONFIG.tc_root_url + "/api/queue"
-        return self \
-        .with_dependencies(task_id) \
-        .with_curl_script(
-            queue_service + "/v1/task/%s/artifacts/public/%s" % (task_id, artifact_name),
-            os.path.join(out_directory, url_basename(artifact_name)),
-        )
-
 
 class MacOsGenericWorkerTask(UnixTaskMixin, GenericWorkerTask):
     """
@@ -812,15 +832,10 @@ def expand_dockerfile(dockerfile):
     return b"\n".join([expand_dockerfile(path), rest])
 
 
-def git_env():
-    assert CONFIG.git_url
-    assert CONFIG.git_ref
-    assert CONFIG.git_sha
-    return {
-        "GIT_URL": CONFIG.git_url,
-        "GIT_REF": CONFIG.git_ref,
-        "GIT_SHA": CONFIG.git_sha,
-    }
+def assert_truthy(x):
+    assert x
+    return x
+
 
 def dict_update_if_truthy(d, **kwargs):
     for key, value in kwargs.items():
@@ -835,3 +850,20 @@ def deindent(string):
 
 def url_basename(url):
     return url.rpartition("/")[-1]
+
+
+@contextlib.contextmanager
+def make_repo_bundle():
+    subprocess.check_call(["git", "config", "user.name", "Decision task"])
+    subprocess.check_call(["git", "config", "user.email", "nobody@mozilla.com"])
+    tree = subprocess.check_output(["git", "show", CONFIG.git_sha, "--pretty=%T", "--no-patch"])
+    message = "Shallow version of commit " + CONFIG.git_sha
+    commit = subprocess.check_output(["git", "commit-tree", tree.strip(), "-m", message])
+    subprocess.check_call(["git", "update-ref", CONFIG.git_bundle_shallow_ref, commit.strip()])
+    subprocess.check_call(["git", "show-ref"])
+    create = ["git", "bundle", "create", "../repo.bundle", CONFIG.git_bundle_shallow_ref]
+    with subprocess.Popen(create) as p:
+        yield
+        exit_code = p.wait()
+        if exit_code:
+            sys.exit(exit_code)
diff --git a/etc/taskcluster/macos/Brewfile b/etc/taskcluster/macos/Brewfile
index ab177ef32d6..c11e49b6c30 100644
--- a/etc/taskcluster/macos/Brewfile
+++ b/etc/taskcluster/macos/Brewfile
@@ -1,11 +1,10 @@
-brew "autoconf@2.13"
-brew "automake"
-brew "cmake"
-brew "openssl"
-brew "pkg-config"
-brew "llvm"
-brew "yasm"
-brew "zlib"
+# Runtime dependencies
 
-# For sccache
-brew "openssl@1.1"
+brew "gnutls"
+brew "gstreamer"
+brew "gst-plugins-base"
+brew "gst-libav"
+brew "gst-plugins-bad"
+brew "gst-plugins-good"
+brew "gst-rtsp-server"
+brew "openssl"
diff --git a/etc/taskcluster/macos/Brewfile-build b/etc/taskcluster/macos/Brewfile-build
new file mode 100644
index 00000000000..c78fe2cea3c
--- /dev/null
+++ b/etc/taskcluster/macos/Brewfile-build
@@ -0,0 +1,12 @@
+# Build dependencies (that are not also runtime dependencies)
+
+brew "autoconf@2.13"
+brew "automake"
+brew "cmake"
+brew "pkg-config"
+brew "llvm"
+brew "yasm"
+brew "zlib"
+
+# For sccache
+brew "openssl@1.1"
diff --git a/etc/taskcluster/macos/Brewfile-gstreamer b/etc/taskcluster/macos/Brewfile-gstreamer
deleted file mode 100644
index 48c1e3b618c..00000000000
--- a/etc/taskcluster/macos/Brewfile-gstreamer
+++ /dev/null
@@ -1,7 +0,0 @@
-brew "gnutls"
-brew "gstreamer"
-brew "gst-plugins-base"
-brew "gst-libav"
-brew "gst-plugins-bad"
-brew "gst-plugins-good"
-brew "gst-rtsp-server"
diff --git a/etc/taskcluster/macos/Brewfile-wpt b/etc/taskcluster/macos/Brewfile-wpt-update
index f563d5e7bf9..f563d5e7bf9 100644
--- a/etc/taskcluster/macos/Brewfile-wpt
+++ b/etc/taskcluster/macos/Brewfile-wpt-update
diff --git a/etc/taskcluster/mock.py b/etc/taskcluster/mock.py
index 9299c7c84df..cbc495ee5b5 100755
--- a/etc/taskcluster/mock.py
+++ b/etc/taskcluster/mock.py
@@ -39,7 +39,7 @@ class Index:
 
 stringDate = str
 slugId = b"<new id>".lower
-Queue = fromNow = MagicMock()
+sys.exit = Queue = fromNow = MagicMock()
 sys.modules["taskcluster"] = sys.modules[__name__]
 sys.dont_write_bytecode = True
 os.environ.update(**{k: k for k in "TASK_ID TASK_OWNER TASK_SOURCE GIT_URL GIT_SHA".split()})
@@ -48,6 +48,7 @@ os.environ["TASKCLUSTER_ROOT_URL"] = "https://community-tc.services.mozilla.com"
 os.environ["TASKCLUSTER_PROXY_URL"] = "http://taskcluster"
 os.environ["NEW_AMI_WORKER_TYPE"] = "-"
 import decision_task
+decision_task.decisionlib.subprocess = MagicMock()
 
 print("\n# Push:")
 decision_task.main("github-push")