No module named 'azure.durable_functions'

[PingvinB]

Version

4.7.0

Description

I'm trying to set up a basic durable functions using the demo code at https://learn.microsoft.com/en-us/azure/azure-functions/durable/quickstart-python-vscode?tabs=windows

I created a new function with func new, added azure-functions-durable>=1.2.4 to requirements.txt, and then added the demo orchestrator code from the quickstart to function_app.py

When starting the function with func start , I get the following error:

[2026-02-20T14:26:58.578Z] Initializing worker process failed
[2026-02-20T14:26:58.579Z] Result: Failure
Type: 
Exception: ModuleNotFoundError: No module named 'azure.durable_functions'. Cannot find module. Please check the requirements.txt file for the missing module. For more info, please refer the troubleshooting guide: https://aka.ms/functions-modulenotfound. Current sys.path: C:\Users\PingvinB\scoop\apps\azure-functions-core-tools\current\workers\python\3.13\WINDOWS\X64 C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\python313.zip C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\DLLs C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib C:\Users\PingvinB\.local\bin C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\site-packages C:\Users\PingvinB\repos\playground\durfuncs
Stack:   File "C:\Users\PingvinB\scoop\apps\azure-functions-core-tools\current\workers\python\3.13\WINDOWS\X64\azure_functions_runtime\handle_event.py", line 99, in worker_init_request
    load_function_metadata(
  File "C:\Users\PingvinB\scoop\apps\azure-functions-core-tools\current\workers\python\3.13\WINDOWS\X64\azure_functions_runtime\handle_event.py", line 410, in load_function_metadata
    _metadata_result = (index_functions(function_path, function_app_directory)) \
  File "C:\Users\PingvinB\scoop\apps\azure-functions-core-tools\current\workers\python\3.13\WINDOWS\X64\azure_functions_runtime\handle_event.py", line 416, in index_functions
    indexed_functions = index_function_app(function_path)
  File "C:\Users\PingvinB\scoop\apps\azure-functions-core-tools\current\workers\python\3.13\WINDOWS\X64\azure_functions_runtime\utils\wrappers.py", line 50, in call
    raise extend_exception_message(e, message)
  File "C:\Users\PingvinB\scoop\apps\azure-functions-core-tools\current\workers\python\3.13\WINDOWS\X64\azure_functions_runtime\utils\wrappers.py", line 46, in call
    return func(*args, **kwargs)
  File "C:\Users\PingvinB\scoop\apps\azure-functions-core-tools\current\workers\python\3.13\WINDOWS\X64\azure_functions_runtime\loader.py", line 176, in index_function_app
    imported_module = importlib.import_module(module_name)
  File "C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\importlib\__init__.py", line 88, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "C:\Users\PingvinB\repos\playground\durfuncs\function_app.py", line 1, in <module>
    import azure.durable_functions as df

Steps to reproduce

Clone https://github.com/PingvinB/demo-func-python-durable

Then run:

python -m venv .venv

.venv/Scripts/activate

python -m pip install -r requirements.txt

func start

[PingvinB]

I'm getting the exact same error with this sample from this repo https://github.com/Azure/azure-functions-durable-python/tree/dev/samples-v2/function_chaining

Same steps (I also tested with v4.6.0):

python -m venv .venv

.venv/Scripts/activate

python -m pip install -r requirements.txt

func start (and chose python runtime as there was no local.settings.json in the sample source)

Output:

 func start
'local.settings.json' found in root directory (C:\Users\PingvinB\repos\sources\azure-functions-durable-python\samples-v2\function_chaining).
Use the up/down arrow keys to select a worker runtime:Starting from 2.0.1-beta.26 it's required to set a language for your project in your settings.
'local.settings.json' found in root directory (C:\Users\PingvinB\repos\sources\azure-functions-durable-python\samples-v2\function_chaining).
Worker runtime 'python' has been set in 'C:\Users\PingvinB\repos\sources\azure-functions-durable-python\samples-v2\function_chaining\local.settings.json'.
Found Python version 3.13.7 (python3).


Azure Functions Core Tools
Core Tools Version:       4.6.0+ab90faafcab539d63cd3d0ce5faf1bca4395fccc (64-bit)
Function Runtime Version: 4.1045.200.25556

Warning: Proxies are not supported in Azure Functions v4. Instead of 'proxies.json', try Azure API Management: https://aka.ms/AAfiueq
[2026-02-23T06:27:20.482Z] Attempt to remove module cache for google._upb but failed with 'google'. Using the original module cache.
[2026-02-23T06:27:20.482Z] Attempt to remove module cache for google._upb but failed with 'google'. Using the original module cache.[2026-02-23T06:27:20.482Z] Attempt to remove module cache for google._upb but failed with 'google'. Using the original module cache.

[2026-02-23T06:27:20.627Z] Error when indexing function. Sys Path:C:\Users\PingvinB\scoop\apps\azure-functions-core-tools\current\workers\python\3.13\WINDOWS\X64 C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\python313.zip C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\DLLs C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib C:\Users\PingvinB\.local\bin C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\site-packages C:\Users\PingvinB\repos\sources\azure-functions-durable-python\samples-v2\function_chaining, python-packages Path exists: False
[2026-02-23T06:27:20.719Z] Initializing worker process failed
[2026-02-23T06:27:20.721Z] Result: Failure
Type:
Exception: ModuleNotFoundError: No module named 'azure.durable_functions'. Cannot find module. Please check the requirements.txt file for the missing module. For more info, please refer the troubleshooting guide: https://aka.ms/functions-modulenotfound. Current sys.path: C:\Users\PingvinB\scoop\apps\azure-functions-core-tools\current\workers\python\3.13\WINDOWS\X64 C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\python313.zip C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\DLLs C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib C:\Users\PingvinB\.local\bin C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\site-packages C:\Users\PingvinB\repos\sources\azure-functions-durable-python\samples-v2\function_chaining
Stack:   File "C:\Users\PingvinB\scoop\apps\azure-functions-core-tools\current\workers\python\3.13\WINDOWS\X64\azure_functions_runtime\handle_event.py", line 99, in worker_init_request
    load_function_metadata(
  File "C:\Users\PingvinB\scoop\apps\azure-functions-core-tools\current\workers\python\3.13\WINDOWS\X64\azure_functions_runtime\handle_event.py", line 410, in load_function_metadata
    _metadata_result = (index_functions(function_path, function_app_directory)) \
  File "C:\Users\PingvinB\scoop\apps\azure-functions-core-tools\current\workers\python\3.13\WINDOWS\X64\azure_functions_runtime\handle_event.py", line 416, in index_functions
    indexed_functions = index_function_app(function_path)
  File "C:\Users\PingvinB\scoop\apps\azure-functions-core-tools\current\workers\python\3.13\WINDOWS\X64\azure_functions_runtime\utils\wrappers.py", line 50, in call
    raise extend_exception_message(e, message)
  File "C:\Users\PingvinB\scoop\apps\azure-functions-core-tools\current\workers\python\3.13\WINDOWS\X64\azure_functions_runtime\utils\wrappers.py", line 46, in call
    return func(*args, **kwargs)
  File "C:\Users\PingvinB\scoop\apps\azure-functions-core-tools\current\workers\python\3.13\WINDOWS\X64\azure_functions_runtime\loader.py", line 176, in index_function_app
    imported_module = importlib.import_module(module_name)
  File "C:\Users\PingvinB\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\importlib\__init__.py", line 88, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "C:\Users\PingvinB\repos\sources\azure-functions-durable-python\samples-v2\function_chaining\function_app.py", line 3, in <module>
    import azure.durable_functions as df
.
[2026-02-23T06:27:20.723Z] Failed to start language worker process for runtime: python. workerId:c4f1f030-cd30-4b77-8302-519d38f8e527