diff options
| -rw-r--r-- | src/buildstream/_frontend/cli.py | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/src/buildstream/_frontend/cli.py b/src/buildstream/_frontend/cli.py index b0eacbb02..8474d3d81 100644 --- a/src/buildstream/_frontend/cli.py +++ b/src/buildstream/_frontend/cli.py @@ -1,3 +1,4 @@ +import multiprocessing import os import sys from functools import partial @@ -12,6 +13,33 @@ from ..utils import UtilError ################################################################## +# Setup multiprocessing # +################################################################## + +# _setup_multiprocessing() +# +# Since Python 3.8, the multiprocessing module defaults to +# the spawn method on MacOS, since the fork method is considered +# unsafe. +# +# However, BuildStream is not compatible with spawn mode so we +# force the default to fork (if available) which works for the most part. +# +# Args: +# force (bool): Whether to force our configuration; useful when being called +# from the test suite. +# +def _setup_multiprocessing(force=False): + # Our tests will not invoke the CLI as a subprocess, but directly from + # Python via Cli.run(). So, we allow `force` to be true in this case, but + # it is not needed when using the CLI normally. + force = "BST_TEST_SUITE" in os.environ + + if multiprocessing.get_start_method() == "spawn" and "fork" in multiprocessing.get_all_start_methods(): + multiprocessing.set_start_method("fork", force=force) + + +################################################################## # Helper classes and methods for Click # ################################################################## @@ -332,6 +360,10 @@ def cli(context, **kwargs): user preferences configuration file. """ + # Configuration for multiprocessing module, that we want to do + # as early as possible. + _setup_multiprocessing() + from .app import App # Create the App, giving it the main arguments |