WIP

3 files changed, 31 insertions, 18 deletions

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 1fe25810a..1c605bdac 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -88,6 +88,12 @@ tests-centos-7.6:
   <<: *tests
   image: registry.gitlab.com/buildstream/buildstream-docker-images/testsuite-centos:7.6.1810-${DOCKER_IMAGE_VERSION}
 
+tests-python-3.8-buster:
+  image: registry.gitlab.com/buildstream/buildstream-docker-images/testsuite-python:3.8-buster-chandan-python3-8-89265968
+  <<: *tests
+  variables:
+    TOXENV: py38
+
 overnight-fedora-30-aarch64:
   image: registry.gitlab.com/buildstream/buildstream-docker-images/testsuite-fedora:aarch64-30-${DOCKER_IMAGE_VERSION}
   tags:
diff --git a/src/buildstream/_scheduler/scheduler.py b/src/buildstream/_scheduler/scheduler.py
index a45da82f9..4e66a034c 100644
--- a/src/buildstream/_scheduler/scheduler.py
+++ b/src/buildstream/_scheduler/scheduler.py
@@ -171,6 +171,14 @@ class Scheduler:
         # Hold on to the queues to process
         self.queues = queues
 
+        # NOTE: Enforce use of `SafeChildWatcher` as we generally don't want
+        # background threads.
+        # In Python 3.8+, `ThreadedChildWatcher` is the default watcher, and not `SafeChildWatcher`
+        # This needs to be done before we call `new_event_loop`, otherwise the loop will not be
+        # setup correctly with the watcher.
+        _watcher = asyncio.SafeChildWatcher()
+        asyncio.set_child_watcher(_watcher)
+
         # Ensure that we have a fresh new event loop, in case we want
         # to run another test in this thread.
         self.loop = asyncio.new_event_loop()
@@ -187,7 +195,6 @@ class Scheduler:
 
         # Watch casd while running to ensure it doesn't die
         self._casd_process = casd_process_manager.process
-        _watcher = asyncio.get_child_watcher()
 
         def abort_casd(pid, returncode):
             asyncio.get_event_loop().call_soon(self._abort_on_casd_failure, pid, returncode)
diff --git a/tox.ini b/tox.ini
index 62737b0ca..85697085d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,7 +2,7 @@
 # Tox global configuration
 #
 [tox]
-envlist = py{35,36,37}
+envlist = py{35,36,37,38}
 skip_missing_interpreters = true
 isolated_build = true
 
@@ -14,22 +14,22 @@ isolated_build = true
 [testenv]
 usedevelop =
     # This is required by Cython in order to get coverage for cython files.
-    py{35,36,37}-!nocover: True
+    py{35,36,37,38}-!nocover: True
 
 commands =
     # Running with coverage reporting enabled
-    py{35,36,37}-!external-!nocover: pytest --basetemp {envtmpdir} --cov=buildstream --cov-config .coveragerc {posargs}
-    py{35,36,37}-!nocover: mkdir -p .coverage-reports
+    py{35,36,37,38}-!external-!nocover: pytest --basetemp {envtmpdir} --cov=buildstream --cov-config .coveragerc {posargs}
+    py{35,36,37,38}-!nocover: mkdir -p .coverage-reports
     external-!nocover: {envpython} {toxinidir}/tests/external_plugins.py {envtmpdir} --cov=buildstream --cov-append {posargs}
-    py{35,36,37}-!external-!nocover: mv {envtmpdir}/.coverage {toxinidir}/.coverage-reports/.coverage.{env:COVERAGE_PREFIX:}{envname}
-    py{35,36,37}-external-!nocover: - mv {envtmpdir}/.coverage {toxinidir}/.coverage-reports/.coverage.{env:COVERAGE_PREFIX:}{envname}
+    py{35,36,37,38}-!external-!nocover: mv {envtmpdir}/.coverage {toxinidir}/.coverage-reports/.coverage.{env:COVERAGE_PREFIX:}{envname}
+    py{35,36,37,38}-external-!nocover: - mv {envtmpdir}/.coverage {toxinidir}/.coverage-reports/.coverage.{env:COVERAGE_PREFIX:}{envname}
     # Running with coverage reporting disabled
-    py{35,36,37}-!external-nocover: pytest --basetemp {envtmpdir} {posargs}
+    py{35,36,37,38}-!external-nocover: pytest --basetemp {envtmpdir} {posargs}
     external-nocover: {envpython} {toxinidir}/tests/external_plugins.py {envtmpdir} {posargs}
 deps =
-    py{35,36,37}: -rrequirements/requirements.txt
-    py{35,36,37}: -rrequirements/dev-requirements.txt
-    py{35,36,37}: -rrequirements/plugin-requirements.txt
+    py{35,36,37,38}: -rrequirements/requirements.txt
+    py{35,36,37,38}: -rrequirements/dev-requirements.txt
+    py{35,36,37,38}: -rrequirements/plugin-requirements.txt
     git+https://gitlab.com/BuildStream/bst-plugins-experimental.git@5b004e5850ab0e987c00c681b2c768f6ae02586b
 
     # Only require coverage and pytest-cov when using it
@@ -58,17 +58,17 @@ passenv =
 # These keys are not inherited by any other sections
 #
 setenv =
-    py{35,36,37}: COVERAGE_FILE = {envtmpdir}/.coverage
-    py{35,36,37}: BST_TEST_HOME = {envtmpdir}
-    py{35,36,37}: BST_TEST_XDG_CACHE_HOME = {envtmpdir}/cache
-    py{35,36,37}: BST_TEST_XDG_CONFIG_HOME = {envtmpdir}/config
-    py{35,36,37}: BST_TEST_XDG_DATA_HOME = {envtmpdir}/share
+    py{35,36,37,38}: COVERAGE_FILE = {envtmpdir}/.coverage
+    py{35,36,37,38}: BST_TEST_HOME = {envtmpdir}
+    py{35,36,37,38}: BST_TEST_XDG_CACHE_HOME = {envtmpdir}/cache
+    py{35,36,37,38}: BST_TEST_XDG_CONFIG_HOME = {envtmpdir}/config
+    py{35,36,37,38}: BST_TEST_XDG_DATA_HOME = {envtmpdir}/share
     # This is required to get coverage for Cython
-    py{35,36,37}-!nocover: BST_CYTHON_TRACE = 1
+    py{35,36,37,38}-!nocover: BST_CYTHON_TRACE = 1
     randomized: PYTEST_ADDOPTS="--random-order-bucket=global"
 
 whitelist_externals =
-    py{35,36,37}:
+    py{35,36,37,38}:
         mv
         mkdir