"Exception: Gradle task assembleDebug failed with exit code 1" when trying to run a Flutter app

Question

After creating a fresh Flutter app and attempting to run it (using Android Studio 3.5.3 or Terminal.app), the following output it given:

% flutter run
Using hardware rendering with device sdk gphone x86 arm. If you notice graphics
artifacts, consider enabling software rendering with
"--enable-software-rendering".
Launching lib/main.dart on sdk gphone x86 arm in debug mode...
                                                                        
FAILURE: Build failed with an exception.                                
                                                                        
* What went wrong:                                                      
A problem occurred configuring root project 'android'.                  
> Could not resolve all artifacts for configuration ':classpath'.       
   > Could not resolve com.android.tools.build:gradle:4.1.0.            
     Required by:                                                       
         project :                                                      
      > Could not resolve com.android.tools.build:gradle:4.1.0.         
         > Could not get resource 'https://dl.google.com/dl/android/maven2/com/android/tools/build/gradle/4.1.0/gradle-4.1.0.pom'.
            > Could not GET 'https://dl.google.com/dl/android/maven2/com/android/tools/build/gradle/4.1.0/gradle-4.1.0.pom'.
               > sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
                                                                        
* Try:                                                                  
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
                                                                        
* Get more help at https://help.gradle.org                              
                                                                        
BUILD FAILED in 3s                                                      
Running Gradle task 'assembleDebug'...                                  
Running Gradle task 'assembleDebug'... Done                         4.7s
Exception: Gradle task assembleDebug failed with exit code 1

This happens if I run the app through Android Studio or through Terminal. Flutter apps run perfectly on the iOS Simulator with no errors.

Further context:

• Android Studio 3.5.3
• macOS Big Sur 11.4
• MacBook Pro 13.3" (Retina, Early 2015, 16GB RAM, 512GB SSD, Intel Core i7)
• Fresh Flutter app
• Flutter 2.2.2
• flutter doctor -v output:

  % flutter doctor -v
  [✓] Flutter (Channel stable, 2.2.2, on macOS 11.4 20F71 darwin-x64, locale en-US)
      • Flutter version 2.2.2 at /Users/peternielsen/.mymods/flutter
      • Framework revision d79295af24 (4 weeks ago), 2021-06-11 08:56:01 -0700
      • Engine revision 91c9fc8fe0
      • Dart version 2.13.3
  
  [✓] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
      • Android SDK at /Users/peternielsen/Library/Android/sdk
      • Platform android-30, build-tools 30.0.3
      • Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
      • Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b49-5587405)
      • All Android licenses accepted.
  
  [✓] Xcode - develop for iOS and macOS
      • Xcode at /Applications/Xcode.app/Contents/Developer
      • Xcode 12.5.1, Build version 12E507
      • CocoaPods version 1.10.1
  
  [✓] Chrome - develop for the web
      • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome
  
  [✓] Android Studio (version 3.5)
      • Android Studio at /Applications/Android Studio.app/Contents
      • Flutter plugin version 44.0.1
      • Dart plugin version 191.8593
      • Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b49-5587405)
  
  [✓] VS Code (version 1.57.1)
      • VS Code at /Applications/Visual Studio Code.app/Contents
      • Flutter extension version 3.24.0
  
  [✓] Connected device (2 available)
      • sdk gphone x86 arm (mobile) • emulator-5554 • android-x86    • Android 11 (API 30) (emulator)
      • Chrome (web)                • chrome        • web-javascript • Google Chrome 91.0.4472.114
  
      • No issues found!
  

Thanks in advance for any help! I don't have any idea why it would fail when the doctor output says no problem - am I missing something?

EDIT:

app/build.gradle:

def localProperties = new Properties()
def localPropertiesFile = rootProject.file('local.properties')
if (localPropertiesFile.exists()) {
    localPropertiesFile.withReader('UTF-8') { reader ->
        localProperties.load(reader)
    }
}

def flutterRoot = localProperties.getProperty('flutter.sdk')
if (flutterRoot == null) {
    throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
}

def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
if (flutterVersionCode == null) {
    flutterVersionCode = '1'
}

def flutterVersionName = localProperties.getProperty('flutter.versionName')
if (flutterVersionName == null) {
    flutterVersionName = '1.0'
}

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"

android {
    compileSdkVersion 30

    sourceSets {
        main.java.srcDirs += 'src/main/kotlin'
    }

    defaultConfig {
        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
        applicationId "com.example.statemanagementzero"
        minSdkVersion 16
        targetSdkVersion 30
        versionCode flutterVersionCode.toInteger()
        versionName flutterVersionName
    }

    buildTypes {
        release {
            // TODO: Add your own signing config for the release build.
            // Signing with the debug keys for now, so `flutter run --release` works.
            signingConfig signingConfigs.debug
        }
    }
}

flutter {
    source '../..'
}

dependencies {
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
}

build.gradle:

buildscript {
    ext.kotlin_version = '1.3.50'
    repositories {
        google()
        jcenter()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:4.1.0'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

rootProject.buildDir = '../build'
subprojects {
    project.buildDir = "${rootProject.buildDir}/${project.name}"
    project.evaluationDependsOn(':app')
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

Answer 1

This error is shown in this line

sun.security.validator.ValidatorException: 
        PKIX path building failed: 
            sun.security.provider.certpath.SunCertPathBuilderException: 
                unable to find valid certification path to requested target

There are some solutions online regarding the problem but it will be easier if you do a clean JDK installation. Otherwise, if want to explore, try this thread instead.