DevTools extensions do not load for offline use cases by default. Requires solution + documentation.

Stack trace:
null

<-- Please describe your problem here. Be sure to include repro steps. -->

I'm working on a DevTools extension,[^2] I initially managed to get my UI to show up, following the steps over here,[^1] then this error started appearing randomly:

Clicking that link brought me here (although as you can see it was unable to populate a stack trace...)

I couldn't really find anything useful in the console, the only 2 errors I noted were the following, with DevTools being unable to find some source maps and some Google Analytics thing not being loaded:

I initially thought this was due to some use of `log` inside my code, but I realised that even without it my basic example wouldn't work...

Then, I realised the one difference from yesterday is the rather poor Internet connection I have right now (thank you Swiss Railways... ), and indeed, after the extension did load (as said, the error is random), I saw this:

It appears that some files are being loaded both from localhost and from some Google CDN (at least the names are the same). And the timing appears to match the delay I see when loading the UI.

Moving over to my mobile connection, suddenly everything worked fine.

Opening the DevTools from Chrome or Safari made no difference.

Is this expected? Did I build the extension UI incorrectly so that it fetches some data remotely?

Thanks!

___
**DevTools version**: 2.31.0
**IDE**: IntelliJ-IDEA
**Connected Device**:
CPU / OS: Web macos
Connected app type: Flutter web (debug build)
Dart Version: 3.3.0-279.3.beta
Flutter Version: 3.19.0-0.4.pre / beta
Framework / Engine: b7e7d46a04 / 98820f0a77

[^1]: https://medium.com/flutter/dart-flutter-devtools-extensions-c8bc1aaf8e5f
[^2]: https://github.com/borgoat/daredux

Reproduce the DevTools extension setup from the linked extension example while offline or on a poor connection, and inspect the remote requests, source-map failures, and analytics errors shown in the report. Done means extensions load reliably without network access and the required offline behavior or setup is documented.

Scritto dal modello di indicizzazione a partire dal testo della issue.