Unable to debug flutter dart code in VS Code, Unverified Breakpoint error

Question

When the code is not running, I can add breakpoint (round red circle), but as soon as it goes into debug mode, it turns into unverified breakpoint (grey hollow circle) and doesn't work at all. However, the same project works well on other systems. I've no idea what the problem is or what the solution would be. I've tried reinstalling flutter SDK numerous times, and have gone through a lot of links on SOF and GitHub regarding this, but none has been helpful enough.

Environment - VS Code, Flutter version: 1.17.2

Flutter doctor -

[✓] Flutter (Channel stable, v1.17.2, on Mac OS X 10.15.3 19D76, locale en-GB)
[✗] Android toolchain - develop for Android devices
    ✗ Unable to locate Android SDK.
      Install Android Studio from: https://developer.android.com/studio/index.html
      On first launch it will assist you in installing the Android SDK components.
      (or visit https://flutter.dev/docs/get-started/install/macos#android-setup for detailed instructions).
      If the Android SDK has been installed to a custom location, set ANDROID_SDK_ROOT to that location.
      You may also want to add it to your PATH environment variable.

[✓] Xcode - develop for iOS and macOS (Xcode 11.3.1)
[!] Android Studio (not installed)
[✓] VS Code (version 1.45.1)
[✓] Connected device (1 available)

! Doctor found issues in 2 categories.

My launch.json File -

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Flutter: Run all Tests",
            "type": "dart",
            "request": "launch",
            "program": "./test/"
        },
        {
            "name": "Dart: Run all Tests",
            "type": "dart",
            "request": "launch",
            "program": "./test/"
        },
        {
            "name": "Dart",
            "type": "dart",
            "request": "launch",
            "program": "bin/main.dart"
        },
    {
        "name": "Dart: Attach to Process",
        "type": "dart",
        "request": "attach"
    },
        {
            "name": "Flutter",
            "request": "launch",
            "type": "dart"
        }
    ]
}

Also, If you know any good alternatives to VSCode and Android Studio for Flutter, please share.

Answer 1

Clicking Run on the top menu in VS code and selecting 'Enable all breakpoints' worked for me. Though you have to place your breakpoint first.

You can also try placing your breakpoint and save your code, then leave the emulator running and close and restart your vs code IDE and run the app with debugging.

Answer 2

i came from mac and always use fn + f5, on windows that means start withouth debugggin, that was my mistake.

Answer 3

 "version": "0.2.0",
  "configurations": [
    {
      "name": "Flutter",
      "request": "launch",
      "type": "dart",
      "flutterMode": "debug"
    }
  ]
}

This is my launch.json file... changing "flutterMode" from profile to debug solved the issue... if you dont have this line adding it could help.

Answer 4

For anybody running into this problem while trying to debug external libraries or sdk code : Make sure you checked "Dart: Debug External Libraries" and "Dart: Debug Sdk Libraries" under Settings > Extensions > Dart & Flutter as described here .

You can also add the following to your settings.json

"dart.debugExternalLibraries": true,
"dart.debugSdkLibraries": true,

Answer 5

For flutter-web I had to change back to <base href="/"> within the web/index.html . A custom href lead to a none-debuggable project.

Answer 6

Your main.dart file's path is not specified right. so in this block

    "name": "Dart",
    "type": "dart",
    "request": "launch",
    "program": "bin/main.dart"

please use

"program": "lib/main.dart"

Answer 7

I was also facing the same issue, I am looking for the exact reason but removing the launch.json file worked for me.

Answer 8

Navigate to the Run Tab and select Dart & Flutter from the drop down menu, finally hit the play button.

Answer 9

Have faced the same issue, resolved by stopping the current active session and click on RUN and select START DEBUGGING. This worked for me.

Answer 10

I faced the same problem with debug in certain dart files, but the other files I could.

Then I realized that it happened when I call another file and this trick would help:

Instead of typing:

import '../form/productdetail.dart';

I replaced with:

import 'package:myapp/form/productdetail.dart';

and it helped.

Answer 11

I had a similar problem. I solved by completely uninstalling and reinstalling Vscode + remove the data. See here

Answer 12

In my case, the parents folder contains special character (#):

.../#Projects/my_project/

Remove the # and the debug goes well:

.../Projects/my_project/