add pip version override for virtualenv in nox

noxfile-template.py

@@ -50,7 +50,10 @@
     # to use your own Cloud project.
     'gcloud_project_env': 'GOOGLE_CLOUD_PROJECT',
     # 'gcloud_project_env': 'BUILD_SPECIFIC_GCLOUD_PROJECT',
-
+    # If you need to use a specific version of pip,
+    # change pip_version_override to the string representation
+    # of the version number, for example, "20.2.4"
+    "pip_version_override": None,
     # A dictionary you want to inject into your test. Don't put any
     # secrets here. These values will override predefined values.
     'envs': {},
@@ -173,6 +176,9 @@ def blacken(session: nox.sessions.Session) -> None:
 
 
 def _session_tests(session: nox.sessions.Session, post_install: Callable = None) -> None:
+    if TEST_CONFIG["pip_version_override"]:
+        pip_version = TEST_CONFIG["pip_version_override"]
+        session.install(f"pip=={pip_version}")
     """Runs py.test for a particular project."""
     if os.path.exists("requirements.txt"):
         if os.path.exists("constraints.txt"):

noxfile_config.py

@@ -32,6 +32,10 @@
     # to use your own Cloud project.
     "gcloud_project_env": "GOOGLE_CLOUD_PROJECT",
     # 'gcloud_project_env': 'BUILD_SPECIFIC_GCLOUD_PROJECT',
+    # If you need to use a specific version of pip,
+    # change pip_version_override to the string representation
+    # of the version number, for example, "20.2.4"
+    "pip_version_override": None,
     # A dictionary you want to inject into your test. Don't put any
     # secrets here. These values will override predefined values.
     "envs": {},