Fix pytest-xdist loadscope splitting on "::" in params

LoadScopeScheduling._split_scope() uses rsplit("::", 1) to
extract the test file scope from a node ID.  When parametrized
test values contain "::" (IPv6 addresses like "cafe:cafe::cafe"
or "::1"), the split lands inside the parameter instead of at
the .py:: boundary.  This creates spurious scopes that get
assigned to different workers, each triggering a full fixture
setup (starting named instances).

Override _split_scope() in conftest.py to split on ".py::"
which is unambiguous.

Six tests in synthrecord/tests_synthrecord.py are affected.
A verification script is included in util/.

Assisted-by: Claude:claude-opus-4-7

diff --git a/bin/tests/system/conftest.py b/bin/tests/system/conftest.py
index 5e8473e424732ae5da10e90110b2da9abebfdb3a..678327a31ffaf38b50062c28e76bd1bfa265524d 100644 (file)
--- a/bin/tests/system/conftest.py
+++ b/bin/tests/system/conftest.py
@@ -62,6 +62,30 @@ PRIORITY_TESTS_RE = Re("|".join(PRIORITY_TESTS))
 SYSTEM_TEST_NAME_RE = Re(f"{SYSTEM_TEST_DIR_GIT_PATH}" + r"/([^/]+)")
 SYMLINK_REPLACEMENT_RE = Re(r"/tests_(.*)\.py")
 
+# ---- Fix pytest-xdist loadscope for node IDs containing "::" ----------
+
+# LoadScopeScheduling._split_scope uses rsplit("::", 1) which breaks when
+# test parameters contain "::" (e.g. IPv6 addresses like "cafe:cafe::cafe").
+# This causes tests from the same file to be assigned to different workers,
+# each paying the full fixture setup cost.  Override to split on ".py::"
+# which is unambiguous.
+# https://github.com/pytest-dev/pytest-xdist/issues/1335
+try:
+    from xdist.scheduler.loadscope import LoadScopeScheduling
+
+    # pylint: disable=protected-access
+    _orig_split_scope = LoadScopeScheduling._split_scope
+
+    def _fixed_split_scope(self, nodeid):
+        if ".py::" in nodeid:
+            return nodeid.split(".py::")[0] + ".py"
+        return _orig_split_scope(self, nodeid)
+
+    LoadScopeScheduling._split_scope = _fixed_split_scope
+    # pylint: enable=protected-access
+except ImportError:
+    pass
+
 # --------------------------- pytest hooks -------------------------------