[DevTools 2.48.0] Network Page stops capturing requests after Clear + Restart (works on 2.42.3)

[P0WERSL1DE]

On Flutter 3.35.4 (Dart 3.9.2, DevTools 2.48.0) the Network tab in Dart DevTools stops capturing any requests after using "Clear" and then doing "Restart" in debug mode.

On the same project with Flutter 3.29.3 (Dart 3.7.2, DevTools 2.42.3) everything works correctly. So the regression appeared between DevTools 2.42.3 and 2.48.0.

Steps to reproduce:

1. Run Flutter app in debug mode (VS Code or Android Studio).
2. Open Dart DevTools → Network.
3. Do some network requests → they are captured correctly.
4. Press "Clear".
5. Restart the app from IDE.
6. No new requests are captured anymore.

Expected result: Network page continues to capture requests after Clear + Restart.

Actual result: Network page stays empty, no requests appear.

Environment: Flutter 3.35.4 • Dart 3.9.2 • DevTools 2.48.0 OS: Windows 10 IDE: VS Code (latest)

Works fine with: Flutter 3.29.3 • Dart 3.7.2 • DevTools 2.42.3

[elliette]

We might want to escalate to a P1 if we are able to consistently reproduce this (FYI @srawlins )

[elliette]

Actually, will mark as P1 now so we don't lose track.

[elliette]

I just hit this after switched DevTools from JS compilation to Wasm compilation (in settings dialog) which triggered a reload of DevTools. After doing so, all requests disappeared and no new requests were shown in the Network panel.

[srawlins]

@elliette what was the app you were connected to? I don't think it's a typical user workflow to close and restart devtools while investigating traffic on an app, is it?

[elliette]

I was using the network_traffic app. The reload doesn't close and restart DevTools, it just reloads the page (triggers https://developer.mozilla.org/en-US/docs/Web/API/Location/reload)

I would expect network traffic to still show up for subsequent requests after the DevTools page was reloaded.

[srawlins]

Oh I see. Very weird. But that is different from OP's issue, right? I take "Restart the app from IDE." to mean restart the app being analyzed by DevTools.

[elliette]

Ah I didn't read the original issue closely enough! Yes different issue

[srawlins]

@P0WERSL1DE thanks for reporting an issue.

I cannot reproduce this with Flutter at head :/. I've tried:

1. Start a networking app with flutter run. OR Start a networking app from VS Code.
2. Start Flutter DevTools. Connect to the networking app. Open network tab.
3. Make requests, see in Network tab.
4. Press clear.
5. Restart the app with "Hot Reload". OR Restart the app with "Restart". ('r' or 'R' when using flutter run.)
6. Make more requests. They still show up.

[Vafin84]

I noticed that dev tools stops displaying queries if their frequency is very high.