Fix flaky test_native_cache_keep by polling for cache file

Replace fixed 2s sleep with wait_for_file polling (up to 10s) for the
cache_keep=True case. On slow CI machines the daemon may not finish
writing the cache file within 2 seconds.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: jpnurmi

tests/assertions.py

@@ -559,11 +559,12 @@ def assert_failed_proxy_auth_request(stdout):
 
 
 def wait_for_file(path, timeout=10.0, poll_interval=0.1):
+    import glob
     import time
 
     deadline = time.time() + timeout
     while time.time() < deadline:
-        if path.exists():
+        if glob.glob(str(path)):
             return True
         time.sleep(poll_interval)
     return False

tests/test_integration_native.py

@@ -19,6 +19,7 @@
 from .assertions import (
     assert_meta,
     assert_session,
+    wait_for_file,
 )
 from .conditions import has_native, is_kcov, is_asan
 
@@ -644,11 +645,9 @@ def test_native_cache_keep(cmake, cache_keep):
         env=env,
     )
 
-    # Wait for crash to be processed
-    time.sleep(2)
-
-    cache_files = list(cache_dir.glob("*.envelope"))
     if cache_keep:
-        assert len(cache_files) == 1
+        assert wait_for_file(cache_dir / "*.envelope")
+        assert len(list(cache_dir.glob("*.envelope"))) == 1
     else:
-        assert len(cache_files) == 0
+        time.sleep(2)
+        assert len(list(cache_dir.glob("*.envelope"))) == 0