CI - deflake Isolated pytest Ubuntu (#6603)

Problem: `test_isolated_packages.py` is still flaky and can fail on
parallel builds of a local `cirq_core` wheel.

Solution: Use per-worker copy of the cirq-core sources so that parallel
builds do not have conflicting build files.

Follow-up to #6593

dev_tools/notebooks/isolated_notebook_test.py

@@ -96,7 +96,7 @@
     "papermill",
     "jupyter",
     # assumed to be part of colab
-    "seaborn~=0.11.1",
+    "seaborn~=0.12",
 ]
 
 

dev_tools/notebooks/notebook_test.py

@@ -26,6 +26,7 @@
 import pytest
 
 from dev_tools import shell_tools
+from dev_tools.modules import list_modules
 from dev_tools.notebooks import filter_notebooks, list_all_notebooks, rewrite_notebook
 from dev_tools.test_utils import only_on_posix
 
@@ -63,9 +64,18 @@ def require_packages_not_changed():
 
     Raise AssertionError if the pre-existing set of Python packages changes in any way.
     """
-    packages_before = set((d.name, d.version) for d in importlib.metadata.distributions())
+    cirq_packages = set(m.name for m in list_modules()).union(["cirq"])
+    packages_before = set(
+        (d.name, d.version)
+        for d in importlib.metadata.distributions()
+        if d.name not in cirq_packages
+    )
     yield
-    packages_after = set((d.name, d.version) for d in importlib.metadata.distributions())
+    packages_after = set(
+        (d.name, d.version)
+        for d in importlib.metadata.distributions()
+        if d.name not in cirq_packages
+    )
     assert packages_after == packages_before
 
 

dev_tools/packaging/isolated_packages_test.py

@@ -32,14 +32,22 @@
 # the "isolation" fails and for example cirq-core would be on the PATH
 @mock.patch.dict(os.environ, {"PYTHONPATH": ""})
 @pytest.mark.parametrize('module', list_modules(), ids=[m.name for m in list_modules()])
-def test_isolated_packages(cloned_env, module):
+def test_isolated_packages(cloned_env, module, tmp_path):
     env = cloned_env("isolated_packages", *PACKAGES)
 
     if str(module.root) != "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 []
+    )
     result = shell_tools.run(
-        f"{env}/bin/pip install --no-clean ./{module.root} ./cirq-core".split(),
+        [f"{env}/bin/pip", "install", f"./{module.root}", *opt_cirq_core],
         stderr=subprocess.PIPE,
         check=False,
     )

dev_tools/requirements/deps/notebook.txt

@@ -13,4 +13,4 @@ papermill~=2.3.2
 -r ../../../cirq-core/cirq/contrib/requirements.txt
 
 # assumed to be part of colab
-seaborn~=0.11.1
+seaborn~=0.12