Error (non-repeatable) "f"File {bf} was modified in the future"" after creating directory/files in AD's "apps" directory

[LupinIII]

What happened?

I was creating a directory for a new "app" in AppDaemon's apps directory. I that directory I created a py file with boilerplate code (a class with an initialize function that prints to log) and I copied in an (empty) __init__.py from another app. I also added the "app" to AD's apps.yaml.

After saving these files I went to Home Assistant's log viewer to see if the boiler plate was working (I did not reload any YAMLs, AD picked it up automatically). There I saw that the log was filling up with the log output below every second. Essentially

  File "/usr/lib/python3.12/site-packages/appdaemon/dependency_manager.py", line 31, in update
    assert new_mtime > mtime, f"File {bf} was modified in the future"

In between these logs I found the message that AD found my new app:

2026-08-15 16:10:05.403052 INFO AppDaemon: New app config: db_states_coalesce
2026-08-15 16:10:05.404465 INFO AppDaemon: Adding thread 1

I guess that is when I saved the apps.yaml, but the errors were already occuring before that (but definitely not before I created the directory/files). So I am quite sure that the actual trigger was either the directory or file creation. All file access was done via an SMB from a Windows PC.

I "resaved" the files (assuming it had to do something with the file date), but AD was still reporting the error every second. Unfortunately I did not try what would happen, if I deleted the files/directory.

Only after restarting AppDaemon the error was gone (without having made any further changes to the files/directory).

I tried to reproduce this error by repeating the steps, but did not manage to. So this might have been a "lucky" one-time-glitch. I just wanted to report it, as AddDaemon did not recover on its own and there might be a deeper issue. As the AD-apps kept working as expected you wouldn't know that the logs are filling up with a long error message every second, unless you looked at the logs.

Version

0.18.5

Installation type

Home Assistant add-on

Relevant log output

2026-08-15 16:28:29.131722 WARNING AppDaemon: ------------------------------------------------------------
2026-08-15 16:28:29.132572 WARNING AppDaemon: Unexpected error during utility()
2026-08-15 16:28:29.133245 WARNING AppDaemon: ------------------------------------------------------------
2026-08-15 16:28:29.137175 WARNING AppDaemon: Traceback (most recent call last):
  File "/usr/lib/python3.12/site-packages/appdaemon/utility_loop.py", line 256, in _loop_iteration_context
    yield timing
  File "/usr/lib/python3.12/site-packages/appdaemon/utility_loop.py", line 207, in loop
    await self.AD.app_management.check_app_updates()
  File "/usr/lib/python3.12/site-packages/appdaemon/app_management.py", line 896, in check_app_updates
    await self.check_app_python_files(update_actions)
  File "/usr/lib/python3.12/site-packages/appdaemon/app_management.py", line 1064, in check_app_python_files
    self.dependency_manager.update_python_files(files)
  File "/usr/lib/python3.12/site-packages/appdaemon/dependency_manager.py", line 198, in update_python_files
    return self.python_deps.update(new_files)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/site-packages/appdaemon/dependency_manager.py", line 68, in update
    return super().update(new_files)
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/site-packages/appdaemon/dependency_manager.py", line 31, in update
    assert new_mtime > mtime, f"File {bf} was modified in the future"
           ^^^^^^^^^^^^^^^^^
TypeError: '>' not supported between instances of 'NoneType' and 'float'
2026-08-15 16:28:29.137947 WARNING AppDaemon: ------------------------------------------------------------

Relevant code in the app or config file that caused the issue

Anything else?

-----------------------------------------------------------
 App: AppDaemon
 Python Apps and Dashboard using AppDaemon 4.x for Home Assistant
-----------------------------------------------------------
 App version: 0.18.5
 You are running the latest version of this app.
 System: Home Assistant OS 18.2  (amd64 / qemux86-64)
 Home Assistant Core: 2026.8.1
 Home Assistant Supervisor: 2026.07.5
-----------------------------------------------------------