如何解决Could not create task ':app:copyFlutterAssetsDebug'构建错误

错误详情 #

执行flutter run时出现以下构建失败：

FAILURE: Build failed with an exception.

* Where:
Build file '/home/elkana/Dev/IdeaProjects/my_app/android/build.gradle' line: 13

* What went wrong:
A problem occurred evaluating root project 'android'.
> A problem occurred configuring project ':app'.
> Could not create task ':app:copyFlutterAssetsDebug'.
> For input string: "7-rc-4"

* 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 8s
Running Gradle task 'assembleDebug'... 9.7s
Error: Gradle task assembleDebug failed with exit code 1

环境信息 #

• Flutter版本：3.19.4（stable通道）
• Gradle版本：8.7-rc-4（候选发布版）
• Android SDK版本：34.0.0
• 项目android/app/build.gradle内容：

plugins {
    id "com.android.application"
    id "kotlin-android"
    id "dev.flutter.flutter-gradle-plugin"
}

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

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

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

android {
    namespace "com.example.my_app"
    compileSdk flutter.compileSdkVersion
    ndkVersion flutter.ndkVersion

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

    kotlinOptions {
        jvmTarget = '1.8'
    }

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

    defaultConfig {
        applicationId "com.example.my_app"
        minSdkVersion flutter.minSdkVersion
        targetSdkVersion flutter.targetSdkVersion
        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 {}

已尝试的无效操作 #

• 切换到Flutter stable通道
• 执行flutter pub upgrade
• 执行flutter pub outdated（确认所有依赖为最新版本）

有效解决方案 #

问题根源 #

Gradle 8.7-rc-4是候选发布版，版本号中的-rc-4格式无法被Flutter Gradle插件正确解析，导致任务创建失败。

解决步骤 #

1. 降级Gradle到正式稳定版
   打开项目根目录下的android/gradle/wrapper/gradle-wrapper.properties文件，修改distributionUrl为Flutter 3.19.4兼容的正式版Gradle（比如8.6）：

   distributionUrl=https\://services.gradle.org/distributions/gradle-8.6-all.zip
   

2. 清理构建缓存
   执行以下命令彻底清理缓存：

   flutter clean
   cd android && ./gradlew clean
   cd ..
   

3. 重新构建项目
   再次执行flutter run即可正常构建。

内容的提问来源于stack exchange，提问作者elisoft-engineer