Tabbular App Bar fails in one project but succeeds in another

[hungrymonkey]

Steps to Reproduce

I am learning how to create mobile apps at the moment. I cannot give an in-depth bug report. I am reporting a bug because similar code does not render.

In lib/views/main.dart, setting the TabBarView seems to fail in one application but succeed in another. Of course, I can manually create a widget list and not use a switch and map statements. I wonder if this code is worthy of a bug report.

working build

https://github.com/hungrymonkey/pregnant_watermelon/tree/567712d47f31e26b53eb6ebc203f73324e404248

https://github.com/hungrymonkey/pregnant_watermelon/blob/567712d47f31e26b53eb6ebc203f73324e404248/lib/main.dart

failed build

https://github.com/hungrymonkey/weather_app/blob/df30be259af667ffd06546eb73795031a5b7a881/lib/main.dart

https://github.com/hungrymonkey/weather_app/tree/df30be259af667ffd06546eb73795031a5b7a881

Step to repoduce

1. download weather_app project
2. Build it
3. Run it
4. TabBarView fails and leave a blank page
5. Error is thrown

I/flutter (31980): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter (31980): The following assertion was thrown during performLayout():
I/flutter (31980): 'package:flutter/src/widgets/sliver.dart': Failed assertion: line 215: 'child != null': is not true.
I/flutter (31980): 
I/flutter (31980): Either the assertion indicates an error in the framework itself, or we should provide substantially
I/flutter (31980): more information in this error message to help you determine and fix the underlying cause.
I/flutter (31980): In either case, please report this assertion by filing a bug on GitHub:
I/flutter (31980):   https://github.com/flutter/flutter/issues/new

Expected Results
Reproduce the same steps with pregnant watermelon commit 7fbb55828d3b0986fcee559bde351a119803bf1b

The TabBarView renders properly.

I am wondering what am I doing differently between pregnant_watermelon and weather_app. The code is almost the same but one fails and the other succeeds. The pages does not matter because I change the page in pregnant_watermelon to the same all MyHomePage and it succeeded.

Either throw warning sign in pregnant_watermelon or throw a better error in my_weather app to figure out what is going on.

Logs

Run your application with flutter run and attach all the log output.

Run flutter analyze and attach any output of that command also.

flutter_run_log.txt

analyze_log.txt

Flutter Doctor

Paste the output of running flutter doctor here.

 [✓] Flutter (on Linux, locale en_US.UTF-8, channel alpha)
    • Flutter at /home/rice/flutter
    • Framework revision d36e2f6191 (4 weeks ago), 2017-06-21 15:09:10 -0700
    • Engine revision b0dee695ec
    • Tools Dart version 1.24.0-dev.6.7

[✓] Android toolchain - develop for Android devices (Android SDK 26.0.0)
    • Android SDK at /home/rice/Android/Sdk
    • Platform android-26, build-tools 26.0.0
    • Java binary at: /opt/android-studio/jre/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_112-release-b06)

[✓] Android Studio (version 2.3)
    • Android Studio at /opt/android-studio
    • Gradle version 3.2
    • Java version OpenJDK Runtime Environment (build 1.8.0_112-release-b06)

[✓] IntelliJ IDEA Community Edition (version 2017.1)
    • Flutter plugin version 15.1
    • Dart plugin version 171.4694.29

[✓] Connected devices
    • SM G900P • 8e90eeee • android-arm • Android 7.1.2 (API 25)

For more information about diagnosing and reporting Flutter bugs, please see https://flutter.io/bug-reports/.

[Piinks]

Hi @hungrymonkey,
It seems some of your reference links are now broken, and when running the weather app you provided, it produced a very different error.
Are you still experiencing this issue? I realize it was some time ago and there may have been a change that resolved this issue.

[hungrymonkey]

Hi @Piinks,

Yes, the links are broken. I deleted the project a long time ago.

The bug is nested scaffolds. I believe another flutter maintainer has commented any nested scaffolds behavior is undefined.

You can close this bug whenever you wish since this bug has many duplicates.

[Piinks]

Ah. Thank you for clarifying. I'm going to see if I can find one of these dupes that we can refer to before closing. Thanks!

[hungrymonkey]

@Piinks The issue is pretty common.

#23106

[Piinks]

Thanks much! I will close this issue then. :)

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.