🐛 Bug Report: AppwriteException: null, Concurrent modification during iteration: Instance(length:2) of '_GrowableList'. (0)

[anandsubbu007]

👟 Reproduction steps

when i tried to log in session.

👍 Expected behavior

👎 Actual Behavior

AppwriteException: null, Concurrent modification during iteration: Instance(length:2) of '_GrowableList'. (0)

🎲 Appwrite version

Version 0.11.x

💻 Operating system

Windows

🧱 Your Environment

Flutter

👀 Have you spent some time to check if this issue has been raised before?

• I checked and didn't find similar issue

🏢 Have you read the Code of Conduct?

• I have read the Code of Conduct

[lohanidamodar]

Please provide the code you are using, SDK version that you are using 🙏🏻

[anandsubbu007]

    client.setEndpoint(endPoint).setProject(projectId).setSelfSigned();
    Account account = Account(client);
    final session = await account.getSession(sessionId: appSetting.sessionId!);
    final doc = await database.getDocument(
        collectionId: CollectionId.User, documentId: vSession.userId);
    final user = AppUser.fromMap(doc.data, doc.$id);

Flutter Windows (Stable Version)

[lohanidamodar]

@anandsubbu007 Flutter SDK version that you are using?

[anandsubbu007]

[√] Flutter (Channel stable, 2.10.4, on Microsoft Windows [Version 10.0.19043.1586], locale en-IN)
    • Flutter version 2.10.4 at C:\My_Program_Setup\Flutter_Components\FVM\stable
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision c860cba910 (11 days ago), 2022-03-25 00:23:12 -0500
    • Engine revision 57d3bac3dd
    • Dart version 2.16.2
    • DevTools version 2.9.2

[√] Android toolchain - develop for Android devices (Android SDK version 31.0.0)        
    • Android SDK at C:\Users\anand\AppData\Local\Android\sdk
    • Platform android-31, build-tools 31.0.0
    • Java binary at: C:\My_Program_Setup\Flutter_Components\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_212-release-1586-b04)       
    • All Android licenses accepted.

[√] Chrome - develop for the web
    • Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe

[√] Visual Studio - develop for Windows (Visual Studio Community 2019 16.11.6)
    • Visual Studio at C:\Program Files (x86)\Microsoft Visual Studio\2019\Community    
    • Visual Studio Community 2019 version 16.11.31829.152
    • Windows 10 SDK version 10.0.19041.0

[√] Android Studio (version 3.6)
    • Android Studio at C:\My_Program_Setup\Flutter_Components\Android Studio
    • Flutter plugin can be installed from:
       https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
       https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 1.8.0_212-release-1586-b04)

[√] VS Code (version 1.66.0)
    • VS Code at C:\Users\anand\AppData\Local\Programs\Microsoft VS Code
    • Flutter extension version 3.36.0

[√] Connected device (3 available)
    • Windows (desktop) • windows • windows-x64    • Microsoft Windows [Version 10.0.19043.1586]
    • Chrome (web)      • chrome  • web-javascript • Google Chrome 100.0.4896.60
    • Edge (web)        • edge    • web-javascript • Microsoft Edge 100.0.1185.29

[√] HTTP Host Availability
    • All required HTTP hosts are available

• No issues found!

[lohanidamodar]

@anandsubbu007 sorry for not being clear enough, I meant the Appwrite's Flutter SDK version that you are using, as your Appwrite server is 0.11 you should not be using the latest version of Appwrite's Flutter SDK. Just wanted to confirm that.

[anandsubbu007]

appwrite: ^4.0.1

Local host: appwrite [v:0.13.4.304]

[lohanidamodar]

@anandsubbu007 This seems to be windows specific issue, we are trying to figure out why. We will update as soon as we have some update. Thank you.

[XeroxDev]

Hey! I've noticed the same bug in the appwrite sdk for flutter.
I'm using version: 5.0.0
I've also debugged it a bit and I've noticed it's crashing in client_io.dart:251 and if stepping further, it's client_io.dart:181

[p4-k4]

flutter: AppwriteException: null, Concurrent modification during iteration: Instance(length:4) of '_GrowableList'. (0)

Getting the same, flutter SDK 6.0.0, iOS.

As discussed with @stnguyen90 on discord, the issue points towards

sdk-for-flutter/lib/src/client_io.dart

Line 137 in 2f1f7c3

final Directory cookieDir = await _getCookiePath();

This init() method is being called 4 times as indicated by the above error.

The suggested workaround for now is to use (for dart/flutter SDK, adapt to suit):

    if (!(client as ClientIO).initialized) {
      await (client as ClientIO).init();
    }

In my case it was only being called 3 times after this, but clears the error either way.
I'll dig a bit deeper when I have time if it's not already seen to.

[lohanidamodar]

flutter: AppwriteException: null, Concurrent modification during iteration: Instance(length:4) of '_GrowableList'. (0)

Getting the same, flutter SDK 6.0.0, iOS.

As discussed with @stnguyen90 on discord, the issue points towards appwrite/sdk-for-flutter@2f1f7c3/lib/src/client_io.dart#L137

This init() method is being called 4 times as indicated by the above error.

The suggested workaround for now is to use (for dart/flutter SDK, adapt to suit):

    if (!(client as ClientIO).initialized) {
      await (client as ClientIO).init();
    }

In my case it was only being called 3 times after this, but clears the error either way. I'll dig a bit deeper when I have time if it's not already seen to.

This is now happening in iOS as well?

[p4-k4]

Has this been sighted yet? Just thought I'd check its on the list TODO. Thanks.

[stnguyen90]

Has this been sighted yet? Just thought I'd check its on the list TODO. Thanks.

@p4-k4, we haven't seen other reports of this so it's not as high of a priority.

[nohli]

Today, I'm facing this issue on iOS simulator (latest versions of everything), when calling await _account.getSessions():

Exception has occurred.
AppwriteException (AppwriteException: null, Concurrent modification during iteration: Instance(length:3) of '_GrowableList'. (0))

Edit: It was probably my fault, because one async method sets _client.setEndpoint(endpoint).setProject(project), and another one is calling await _databases.createDocument(...)