Invalid import in cache_lock.py – portalocker.exceptions does not exist

[daga05]

We're encountering a runtime failure using msal-extensions==1.3.1 due to an invalid reference to portalocker.exceptions in cache_lock.py:

LockError = portalocker.exceptions.LockException

This causes authentication logic to break with:

AttributeError: module 'portalocker' has no attribute 'exceptions'

The current version of the portalocker package (e.g., 2.10.1) no longer exposes an exceptions module or attribute at the top level.

Suggested Fix:

Change the reference to:

import portalocker
LockError = portalocker.LockException

Confirmed Environment:

msal-extensions: 1.3.1
portalocker: 2.10.1
Python 3.11
Runtime: Azure App Service (Linux)

Please let us know if a fix can be included in the next release. We're happy to help validate or contribute a PR.

[junior-juarez-MSFT]

Here is the full exception

CertificateCredential.get_token failed: Authentication failed: module 'portalocker' has no attribute 'exceptions'

[rayluo]

But I am not able to reproduce the issue.

pip list
Package        Version
-------------- -------
pip            25.0.1
portalocker    2.10.1
security_state 0.0.0
setuptools     78.1.0
wheel          0.45.1
py3: commands[1]> python -c 'import portalocker; portalocker.exceptions.LockException; print("import successfully")'
import successfully

Can you share a way to reproduce it?

[rayluo]

Further suggestions.

The issue WOULD happen if BOTH of the following conditions were met:

1. Customer's code explicitly uses the cache_lock.py
2. Customer's environment does NOT have portalocker installed.

HOWEVER, neither of the two conditions should occur.

• #1 is not the correct way to use MSAL EX. Please follow our samples.
• #2 i.e. the absence of portalocker shall not be an issue if the caller did #1 right, because portalocker is no longer required since MSAL EX 1.3.x. If customer fixes #1, they won't need to fiddle with portalocker.