CI - deflake "Isolated pytest Ubuntu" (#7806)

Problem: The CI test "Isolated pytest Ubuntu" may still fail when
cirq-core in the repository is copied with intermediate build files.

Solution: Use a dedicated copy of cirq-core sources for installation in
each module test including when testing cirq-core itself.

Also use `logging` instead of `print` in the `cloned_env` fixture as
`logging.info` is easier to recover from parallel pytest runs
(run pytest with the `--log-level=info` option).

Follow-up to #6603

Author: pavoljuhas

dev_tools/conftest.py

@@ -14,6 +14,7 @@
 
 from __future__ import annotations
 
+import logging
 import os
 import shutil
 import sys
@@ -28,6 +29,8 @@
 from dev_tools import shell_tools
 from dev_tools.env_tools import create_virtual_env
 
+_LOGGER = logging.getLogger(__name__)
+
 
 @pytest.fixture(scope="session", autouse=True)
 def disable_local_gcloud_credentials(tmp_path_factory):
@@ -81,9 +84,13 @@ def base_env_creator(env_dir_name: str, *pip_install_args: str) -> Path:
         base_dir = base_temp_path / env_dir_name
         with FileLock(str(base_dir) + ".lock"):
             if _check_for_reuse_or_recreate(base_dir):
-                print(f"Pytest worker [{worker_id}] is reusing {base_dir} for '{env_dir_name}'.")
+                _LOGGER.info(
+                    f"Pytest worker [{worker_id}] is reusing {base_dir} for '{env_dir_name}'."
+                )
             else:
-                print(f"Pytest worker [{worker_id}] is creating {base_dir} for '{env_dir_name}'.")
+                _LOGGER.info(
+                    f"Pytest worker [{worker_id}] is creating {base_dir} for '{env_dir_name}'."
+                )
                 _create_base_env(base_dir, pip_install_args)
 
         clone_dir = base_temp_path / str(uuid.uuid4())
@@ -112,7 +119,7 @@ def _create_base_env(base_dir: Path, pip_install_args: tuple[str, ...]):
         except BaseException as ex:
             # cleanup on failure
             if base_dir.is_dir():
-                print(f"Removing {base_dir}, due to error: {ex}")
+                _LOGGER.info(f"Removing {base_dir}, due to error: {ex}")
                 shutil.rmtree(base_dir)
             raise
 

dev_tools/packaging/isolated_packages_test.py

@@ -37,19 +37,16 @@
 def test_isolated_packages(cloned_env, module, tmp_path) -> None:
     env = cloned_env("isolated_packages", *PACKAGES)
 
-    if str(module.root) != "cirq-core":
+    if module.name != "cirq-core":
         assert f'cirq-core=={module.version}' in module.install_requires
 
-    # TODO: Remove after upgrading package builds from setup.py to PEP-517
     # Create per-worker copy of cirq-core sources so that parallel builds
     # of cirq-core wheel do not conflict.
-    opt_cirq_core = (
-        [str(shutil.copytree("./cirq-core", tmp_path / "cirq-core"))]
-        if str(module.root) != "cirq-core"
-        else []
-    )
+    cirq_core_copy = shutil.copytree("./cirq-core", tmp_path / "cirq-core")
+    # avoid specifying cirq-core twice
+    opt_module_dir = [] if module.name == "cirq-core" else [f"./{module.root}"]
     result = shell_tools.run(
-        [f"{env}/bin/pip", "install", f"./{module.root}", *opt_cirq_core],
+        [f"{env}/bin/pip", "install", cirq_core_copy, *opt_module_dir],
         stderr=subprocess.PIPE,
         check=False,
     )