(Hopefully) resolve flaky tests

Mark tests that rely on global state as serial-execution-only

Assisted-By: claude-opus-4.6

Author: dralley

pulp_rpm/tests/functional/api/test_pulpimport.py

@@ -245,6 +245,7 @@ def test_distribution_tree_import(
         assert trees.count == 1
 
 
+@pytest.mark.serial  # Runs orphan cleanup to create a content-free zone; conflicts with parallel tests
 def test_clean_import(
     rpm_repository_api,
     import_export_repositories,
@@ -286,6 +287,7 @@ def test_clean_import(
     assert rpm_repository_api.list().count == existing_repos
 
 
+@pytest.mark.serial  # Runs orphan cleanup to create a content-free zone; conflicts with parallel tests
 def test_create_missing_repos(
     init_and_sync,
     rpm_rpmremote_api,

pulp_rpm/tests/functional/api/test_repo_sizes.py

@@ -1,6 +1,8 @@
 import json
 import subprocess
 
+import pytest
+
 from pulp_rpm.tests.functional.constants import (
     RPM_UNSIGNED_FIXTURE_URL,
     RPM_UNSIGNED_FIXTURE_SIZE,
@@ -9,6 +11,7 @@
 )
 
 
+@pytest.mark.serial  # Asserts exact disk-size; parallel immediate syncs share artifacts and inflate it
 def test_repo_size(init_and_sync, delete_orphans_pre, monitor_task, pulpcore_bindings):
     """Test that RPM repos correctly report their on-disk artifact sizes."""
     monitor_task(pulpcore_bindings.OrphansCleanupApi.cleanup({"orphan_protection_time": 0}).task)
@@ -39,6 +42,7 @@ def test_repo_size(init_and_sync, delete_orphans_pre, monitor_task, pulpcore_bin
     assert report["on-demand-size"] == 0
 
 
+@pytest.mark.serial  # Asserts exact disk-size; parallel immediate syncs share artifacts and inflate it
 def test_kickstart_repo_size(init_and_sync, delete_orphans_pre, monitor_task, pulpcore_bindings):
     """Test that kickstart RPM repos correctly report their on-disk artifact sizes."""
     monitor_task(pulpcore_bindings.OrphansCleanupApi.cleanup({"orphan_protection_time": 0}).task)