Help to flet build web

[Guilherme-RFerrari]

Hello friends, I need help to complete the 'flet build web' command.

I am initially conducting some tests. First, I created a folder for my project, then created a Python virtual environment with 'python -m venv venv', activated my Python virtual environment with 'cd venv/scripts/activate', and installed Flet with 'pip install flet'. After that, I started a new Flet project through the VSCode terminal with 'flet create --project-name teste_flet'. I noticed that running main.py comes with the counter template, and I only added 'view=ft.AppView.WEB_BROWSER' in main.py.

Now, just for testing purposes, even though it's the default counter template, I need to run the test and check how the build goes.

So I executed 'flet build web', and this error occurred:

(venv) PS C:\Users\gferrari\Desktop\DEV\teste_flet> flet build web
[18:02:49] Created Flutter bootstrap project from gh:flet-dev/flet-build-template with ref 0.25.2 ✅           
           Customized app icons and splash images ✅                                                           
[18:02:56] Generated app icons ✅                                                                              
[18:03:00] Generated splash screens ✅                                                                         
[18:03:21] Packaged Python app ✅                                                                              
[18:03:43] Resolving dependencies...                                                                           
           Downloading packages...                                                                             
             archive 3.6.1 (4.0.1 available)                                                                   
             characters 1.3.0 (1.4.0 available)                                                                
             clock 1.1.1 (1.1.2 available)                                                                     
             collection 1.19.0 (1.19.1 available)                                                              
             flutter_lints 2.0.3 (5.0.0 available)                                                             
             image 4.3.0 (4.5.0 available)                                                                     
             intl 0.19.0 (0.20.1 available)                                                                    
             js 0.6.7 (0.7.1 available)                                                                        
             lints 2.1.1 (5.1.0 available)                                                                     
             material_color_utilities 0.11.1 (0.12.0 available)                                                
             meta 1.15.0 (1.16.0 available)                                                                    
             path 1.9.0 (1.9.1 available)                                                                      
             sensors_plus 4.0.2 (6.1.1 available)                                                              
             sensors_plus_platform_interface 1.2.0 (2.0.1 available)                                           
             serious_python 0.8.3 (0.8.4 available)                                                            
             toml 0.15.0 (0.16.0 available)                                                                    
             url_strategy 0.2.0 (discontinued)                                                                 
           ! wakelock_plus 1.2.8 (overridden)                                                                  
           ! web 1.1.0 (overridden)                                                                            
             web_socket_channel 2.4.5 (3.0.1 available)                                                        
           ! window_manager 0.4.3 (overridden)                                                                 
           Got dependencies!                                                                                   
           1 package is discontinued.                                                                          
           18 packages have newer versions incompatible with dependency constraints.                           
           Try `flutter pub outdated` for more information.                                                    
                                                                                                               
           Compiling lib\main.dart for the Web...                                                              
           Compiling lib\main.dart for the Web...                             19,8s                            
                                                                                                               
           Target dart2js failed: ProcessException: Process exited abnormally with exit code 1:                
           ../../../../../AppData/Local/Pub/Cache/hosted/pub.dev/flet-0.25.2/lib/src/utils/theme.dart:356:28:  
           Error: A value of type 'TabBarThemeData' can't be returned from a function with return type         
           'TabBarTheme?'.                                                                                     
            - 'TabBarThemeData' is from 'package:flutter/src/material/tab_bar_theme.dart'                      
           ('../../../../../flutter/packages/flutter/lib/src/material/tab_bar_theme.dart').                    
            - 'TabBarTheme' is from 'package:flutter/src/material/tab_bar_theme.dart'                          
           ('../../../../../flutter/packages/flutter/lib/src/material/tab_bar_theme.dart').                    
             return theme.tabBarTheme.copyWith(                                                                
                                      ^                                                                        
           ../../../../../AppData/Local/Pub/Cache/hosted/pub.dev/flet-0.25.2/lib/src/utils/theme.dart:438:28:  
           Error: A value of type 'DialogThemeData' can't be returned from a function with return type         
           'DialogTheme?'.                                                                                     
            - 'DialogThemeData' is from 'package:flutter/src/material/dialog_theme.dart'                       
           ('../../../../../flutter/packages/flutter/lib/src/material/dialog_theme.dart').                     
            - 'DialogTheme' is from 'package:flutter/src/material/dialog_theme.dart'                           
           ('../../../../../flutter/packages/flutter/lib/src/material/dialog_theme.dart').                     
             return theme.dialogTheme.copyWith(                                                                
                                      ^                                                                        
           ../../../../../AppData/Local/Pub/Cache/hosted/pub.dev/flet-0.25.2/lib/src/utils/theme.dart:482:26:  
           Error: A value of type 'CardThemeData' can't be returned from a function with return type           
           'CardTheme?'.                                                                                       
            - 'CardThemeData' is from 'package:flutter/src/material/card_theme.dart'                           
           ('../../../../../flutter/packages/flutter/lib/src/material/card_theme.dart').                       
            - 'CardTheme' is from 'package:flutter/src/material/card_theme.dart'                               
           ('../../../../../flutter/packages/flutter/lib/src/material/card_theme.dart').                       
             return theme.cardTheme.copyWith(                                                                  
                                    ^                                                                          
           Error: Compilation failed.                                                                          
             Command: C:\Users\gferrari\flutter\bin\cache\dart-sdk\bin\dart.exe                                
           C:\Users\gferrari\flutter\bin\cache\dart-sdk\bin\snapshots\dart2js.dart.snapshot                    
           --platform-binaries=C:\Users\gferrari\flutter\bin\cache\flutter_web_sdk\kernel                      
           --invoker=flutter_tool -Ddart.vm.product=true -DFLUTTER_WEB_AUTO_DETECT=false                       
           -DFLUTTER_WEB_USE_SKIA=true                                                                         
           -DFLUTTER_WEB_CANVASKIT_URL=https://www.gstatic.com/flutter-canvaskit/83bacfc52569459a4a654727cad254
           6820cb0d6a/ --native-null-assertions --no-source-maps -o                                            
           C:\Users\gferrari\Desktop\DEV\teste_flet\build\flutter\.dart_tool\flutter_build\ed095c3a0a9554e13602
           e034ae931256\app.dill                                                                               
           --packages=C:\Users\gferrari\Desktop\DEV\teste_flet\build\flutter\.dart_tool\package_config.json    
           --cfe-only                                                                                          
           C:\Users\gferrari\Desktop\DEV\teste_flet\build\flutter\.dart_tool\flutter_build\ed095c3a0a9554e13602
           e034ae931256\main.dart                                                                              
           #0      RunResult.throwException (package:flutter_tools/src/base/process.dart:122:5)                
           #1      _DefaultProcessUtils.run (package:flutter_tools/src/base/process.dart:389:19)               
           <asynchronous suspension>                                                                           
           #2      Dart2JSTarget.build (package:flutter_tools/src/build_system/targets/web.dart:202:5)         
           <asynchronous suspension>                                                                           
           #3      _BuildInstance._invokeInternal                                                              
           (package:flutter_tools/src/build_system/build_system.dart:891:9)                                    
           <asynchronous suspension>                                                                           
           #4      Future.wait.<anonymous closure> (dart:async/future.dart:520:21)                             
           <asynchronous suspension>                                                                           
           #5      _BuildInstance.invokeTarget                                                                 
           (package:flutter_tools/src/build_system/build_system.dart:829:32)                                   
           <asynchronous suspension>                                                                           
           #6      Future.wait.<anonymous closure> (dart:async/future.dart:520:21)                             
           <asynchronous suspension>                                                                           
           #7      _BuildInstance.invokeTarget                                                                 
           (package:flutter_tools/src/build_system/build_system.dart:829:32)                                   
           <asynchronous suspension>                                                                           
           #8      FlutterBuildSystem.build (package:flutter_tools/src/build_system/build_system.dart:651:16)  
           <asynchronous suspension>                                                                           
           #9      WebBuilder.buildWeb (package:flutter_tools/src/web/compile.dart:92:34)                      
           <asynchronous suspension>                                                                           
           #10     BuildWebCommand.runCommand (package:flutter_tools/src/commands/build_web.dart:233:5)        
           <asynchronous suspension>                                                                           
           #11     FlutterCommand.run.<anonymous closure>                                                      
           (package:flutter_tools/src/runner/flutter_command.dart:1450:27)                                     
           <asynchronous suspension>                                                                           
           #12     AppContext.run.<anonymous closure> (package:flutter_tools/src/base/context.dart:153:19)     
           <asynchronous suspension>                                                                           
           #13     CommandRunner.runCommand (package:args/command_runner.dart:212:13)                          
           <asynchronous suspension>                                                                           
           #14     FlutterCommandRunner.runCommand.<anonymous closure>                                         
           (package:flutter_tools/src/runner/flutter_command_runner.dart:421:9)                                
           <asynchronous suspension>                                                                           
           #15     AppContext.run.<anonymous closure> (package:flutter_tools/src/base/context.dart:153:19)     
           <asynchronous suspension>                                                                           
           #16     FlutterCommandRunner.runCommand                                                             
           (package:flutter_tools/src/runner/flutter_command_runner.dart:364:5)                                
           <asynchronous suspension>                                                                           
           #17     run.<anonymous closure>.<anonymous closure> (package:flutter_tools/runner.dart:131:9)       
           <asynchronous suspension>                                                                           
           #18     AppContext.run.<anonymous closure> (package:flutter_tools/src/base/context.dart:153:19)     
           <asynchronous suspension>                                                                           
           #19     main (package:flutter_tools/executable.dart:94:3)                                           
           <asynchronous suspension>                                                                           
                                                                                                               
           Error: Failed to compile application for the Web.                                                   
                                                                                                               
           Error building Flet app - see the log of failed command above.                                      
[18:03:49] Doctor summary (to see all details, run flutter doctor -v):                                         
           [✓] Flutter (Channel stable, 3.27.0, on Microsoft Windows , locale pt-BR)                           
           [✓] Windows Version (Installed version of Windows is version 10 or higher)                          
           [✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0)                    
           [✓] Chrome - develop for the web                                                                    
           [✓] Visual Studio - develop Windows apps (Visual Studio Community 2022 17.11.5)                     
           [✓] Android Studio (version 2023.2)                                                                 
           [✓] VS Code (version 1.96.0)                                                                        
           [✓] Connected device (3 available)                                                                  
           [✓] Network resources                                                                               
                                                                                                               
           • No issues found!

[FeodorFitsner]

Flutter 3.27 is not yet supported, sorry. Please downgrade your Flutter installation to the latest 3.24.x.

[ndonkoHenri]

Link to issue: #4548