Fixed #30323 -- Fixed spurious autoreload failures.

[orf]

Ticket: https://code.djangoproject.com/ticket/30323

A few fixes and changes here:

1. Loading the urlconf module can result in SyntaxErrors. We now swallow them to prevent the reloader from quitting.

2. Simplified the ensure_echo_on method

3. Simplified the stat autoreloader. The implementation is now pretty much exactly the same as the one in Flask/Werkzeug

4. The thread running Django itself is now named django-main-thread to help with tracebacks.

[carltongibson]

Hey @orf. Thanks for your efforts here. Is it worth you combining fixes into a single PR here (separate commits if you want) whilst you're working on it? (I don't mind: what do you think?)

[orf]

Sure thing, if that's easier to review. I'll bundle them all into this PR 👍

[carltongibson]

Works for me. Let me know if I can help at all testing and such. 👍

[orf]

I've made a few fixes here. When I originally wrote the StatReloader I wanted it to be able to pick up newly created files (that have been watched but do not exist yet, like translation files) as well as files that have been modified.

I did this by tracking the time.time() of the last loop and comparing it to any new files we have picked up. As far as I can tell on some Windows platforms and in some situations this caused issues which I cannot quite explain.

So I've just simplified the stat reloader to be pretty much identical to the one in Werkzeug. I will see if I can find anyone to test this (I've pushed it to a fix-stat-reloader branch on my fork, which is right off 2.2).

[carltongibson]

Hey @orf: anything your end still to do here? (Thanks!)

[orf]

Not on this PR, I think this is complete and ready to go. However there is #11263 which I would say should be included as well if possible, even though it’s not marked as a release blocker.

[felixxm]

@orf Thanks for this patch 👍 I left two comments.