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xdist continues test execution in the background with '--exitfirst' #420
Description
When running pytest with --exitfirst or --maxfail=<some non zero value>, the main pytest session exits on the first failure as expected. However, the test workers are still executing the tests in the background.
The --exitfirst flag is very powerful when investigating test failures in scenarios where the tests have side-effects and starting the next test may destroy valuable execution traces 😃
Here is a minimal test suite to reproduce the issue:
import os
import unittest
logfile = open('/tmp/pytest.log', 'a')
worker = os.environ.get('PYTEST_XDIST_WORKER', 'single')
def log(line):
logfile.write("[%s] %s\n" % (worker, line))
class TestPytest(unittest.TestCase):
@classmethod
def setUpClass(cls):
log("setUpClass")
def setUp(self):
log("setUp")
def test_1(self):
log("test_1")
def test_2(self):
log("test_2")
assert False
def test_3(self):
log("test_3")Test run with xdist:
rm -f /tmp/pytest.log && pytest-3 -x -d --tx popen//python=python3 test_pytest.py; cat /tmp/pytest.log
(actual test output redacted)
[gw0] setUpClass
[gw0] setUp
[gw0] test_1
[gw0] setUp
[gw0] test_2
[gw0] setUp
[gw0] test_3
Test run without xdist:
rm -f /tmp/pytest.log && pytest-3 -x test_pytest.py; cat /tmp/pytest.log
(actual test output redacted)
[single] setUpClass
[single] setUp
[single] test_1
[single] setUp
[single] test_2
Here is a partial patch to address this issue:
diff --git a/xdist/remote.py b/xdist/remote.py
index 346d6e5..36fc577 100644
--- a/xdist/remote.py
+++ b/xdist/remote.py
@@ -85,6 +85,8 @@ class WorkerInteractor:
duration = time.time() - start
self.sendevent("runtest_protocol_complete", item_index=self.item_index,
duration=duration)
+ if self.session.shouldfail:
+ raise self.session.Failed(self.session.shouldfail)
def pytest_collection_finish(self, session):
self.sendevent(
@@ -106,6 +108,8 @@ class WorkerInteractor:
data["worker_id"] = self.workerid
assert self.session.items[self.item_index].nodeid == report.nodeid
self.sendevent("testreport", data=data)
+ if report.failed and self.config.getvalue("maxfail"):
+ self.session.shouldfail = "Immediately exit worker on failure"
def pytest_collectreport(self, report):
data = serialize_report(report)When maxfail is set, this patch causes the worker to exit on the first failure. This implements the behavior of --exitfirst in the worker. However, when using --maxfail=<some non zero/non one value>, this produces a stacktrace.
Activity
DawnofGenX commentedon Oct 6, 2026
/take
Reproduced on current master (56725a1): with
-n2 --exitfirst, aftertest_01fails on gw0, gw1 still runstest_03/test_04/test_05— the workers aren't told to stop. Without xdist the run stops immediately. I'll look at the controller's shutdown path and the worker loop.