From c4f7a8412c8abb245fb3a422888db68a9881a823 Mon Sep 17 00:00:00 2001
From: Neil Ketteringham <53205839+Neilk1021@users.noreply.github.com>
Date: Fri, 31 Jul 2026 18:53:44 +0000
Subject: [PATCH] fix(pyamber): Invalidate cache while loading executor_def.
 (#7173)

### What changes were proposed in this PR?
This PR calls `importlib.invalidate_caches()` prior to importing newly
written UDF modules in `ExecutorManager.load_executor_definition`.

### Any related issues, documentation, discussions?
Fixes #7126

### How was this PR tested?
Tested with existing Python unit tests:
*
`amber/src/test/python/core/architecture/managers/test_executor_manager.py::TestUpdateExecutor::test_repeated_updates_keep_carrying_the_running_state`

Verified that rapid sequential executor updates cleanly load without
throwing `ModuleNotFoundError`.

### Was this PR authored or co-authored using generative AI tooling?
No.

(backported from commit 24a20c8e4b6f876082be35f6f5fba4833a122de8)
---
 .../main/python/core/architecture/managers/executor_manager.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/amber/src/main/python/core/architecture/managers/executor_manager.py b/amber/src/main/python/core/architecture/managers/executor_manager.py
index 7f2249476ad..375033ad60c 100644
--- a/amber/src/main/python/core/architecture/managers/executor_manager.py
+++ b/amber/src/main/python/core/architecture/managers/executor_manager.py
@@ -99,6 +99,9 @@ def load_executor_definition(self, code: str) -> type(Operator):
             f"{Path(self.fs.getsyspath('/')).joinpath(file_name)}."
         )
 
+        # Clear importlib's directory listing cache so freshly written
+        # temporary modules are discoverable on systems with coarse mtime.
+        importlib.invalidate_caches()
         # gen_module_file_name guarantees module_name is unique across
         # the process, so import_module will always cleanly load source
         # from the tmp fs we just wrote — no re-import / reload dance.