FileNotFoundError during scantree() caused by broken symlink

[fdemmer]

Python Version

3.9.18

Django Version

4.1.13

Package Version

6.7.0

Description

A few days ago an unfortunate chain of events lead to a script producing a broken symlink in my staticfiles path, a subsequent automatic reload of the server caused whitenoise to update its file dict, ultimately leading to a FileNotFoundError in scantree() and crashing the whole thing.

I propose exception handling and a warning in #604

Not sure if there is a better way to test the broken symlink, other than committing one 🤔

[adamchainz]

Per comment on the issue, I am not convinced Whitenoise should hide this error. Maybe if others encounter it, we can reopen and discuss.