fix(python): always use fake token in E2E tests to prevent hang

The E2E test harness overrides XDG_CONFIG_HOME to an isolated temp
directory. When running locally (not CI), github_token was None, so
the CLI defaulted to use_logged_in_user=True but found no credentials
in the empty temp dir. This caused a silent auth failure — the CLI
logged 'Session was not created with authentication info' but never
emitted a session.error event, making send_and_wait() hang forever.

Since E2E tests use a replaying proxy with canned responses, real
auth is never needed. Always pass the fake token.

Author: brettcannon

python/e2e/test_session.py

@@ -160,13 +160,12 @@ async def test_should_resume_a_session_using_a_new_client(self, ctx: E2ETestCont
         assert "2" in answer.data.content
 
         # Resume using a new client
-        github_token = "fake-token-for-e2e-tests" if os.environ.get("CI") == "true" else None
         new_client = CopilotClient(
             {
                 "cli_path": ctx.cli_path,
                 "cwd": ctx.work_dir,
                 "env": ctx.get_env(),
-                "github_token": github_token,
+                "github_token": "fake-token-for-e2e-tests",
             }
         )
 

python/e2e/testharness/context.py

@@ -53,14 +53,17 @@ async def setup(self):
         self.proxy_url = await self._proxy.start()
 
         # Create the shared client (like Node.js/Go do)
-        # Use fake token in CI to allow cached responses without real auth
-        github_token = "fake-token-for-e2e-tests" if os.environ.get("CI") == "true" else None
+        # Always use a fake token since E2E tests use a replaying proxy with
+        # canned responses — real auth is never needed. Without a token the CLI
+        # looks for credentials under XDG_CONFIG_HOME, which points to an
+        # isolated temp dir and is therefore empty, causing a silent auth
+        # failure that makes tests hang.
         self._client = CopilotClient(
             {
                 "cli_path": self.cli_path,
                 "cwd": self.work_dir,
                 "env": self.get_env(),
-                "github_token": github_token,
+                "github_token": "fake-token-for-e2e-tests",
             }
         )