Error:(11, 0) Declaring custom 'clean' task when using the standard Gradle lifecycle plugins is not allowed

Question

Hello i am working now on android application with 2 modules the first is my app with buildgradle like

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.alexvasilkov:android-sign-release:0.8.1'
    }
}

apply plugin: 'com.android.application'
apply plugin: 'com.alexvasilkov.sign'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.0"
    useLibrary 'org.apache.http.legacy'
    defaultConfig {
        applicationId "dz.condorpos"
        minSdkVersion 17
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }

    signingConfigs {
        release {
            storeFile file("foldable-layout-release-key.keystore")
            keyAlias "release"
        }
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
            signingConfig signingConfigs.release
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile project(':library')
    compile 'com.android.support:appcompat-v7:25.3.1'
    compile 'com.android.support:design:25.3.1'
    compile 'com.squareup.okhttp3:okhttp:3.8.1'
    compile 'com.github.barteksc:android-pdf-viewer:1.4.0'
    compile 'com.android.support:cardview-v7:25.3.1'
    compile 'com.github.bumptech.glide:glide:3.7.0'
    compile 'com.alexvasilkov:android-commons:2.0.2'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    compile 'com.afollestad:easyvideoplayer:0.3.0'
    compile 'com.google.firebase:firebase-auth:10.0.1'
    compile 'de.hdodenhof:circleimageview:2.1.0'
    compile 'com.google.firebase:firebase-database:10.0.1'
    compile 'com.theartofdev.edmodo:android-image-cropper:2.4.+'
    compile 'com.google.firebase:firebase-storage:10.0.1'
    compile 'com.squareup.picasso:picasso:2.5.2'

    testCompile 'junit:junit:4.12'
}

apply plugin: 'com.google.gms.google-services'

the second module is a library included to my project here is the buildgradle(module:library):

apply plugin: 'com.android.library'
android {
    compileSdkVersion 25
    buildToolsVersion '25.0.2'

    defaultConfig {
        minSdkVersion 14
        targetSdkVersion 25
    }
}
// New version can be uploaded with 'gradlew clean :library:jar :library:uploadArchives'
apply from: 'gradle-mvn-push.gradle'

dependencies {
}

the project buildgradle is like :

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {

        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.3'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
        classpath 'com.google.gms:google-services:3.0.0'
    }
}

allprojects { project ->
    repositories {
        jcenter()
        maven { url 'https://dl.bintray.com/drummer-aidan/maven' }
    }
    // Enabling checkstyle for all sub projects
    project == rootProject || project.afterEvaluate {
        project.apply plugin: 'checkstyle'

        project.extensions.getByName('checkstyle').with {
            toolVersion = '6.15'
            configFile file("${rootDir}/checkstyle.xml")
        }

        task checkstyle(type: Checkstyle) {
            source 'src'
            include '**/*.java', '**/*.xml'
            classpath = files()
        }

        project.tasks.getByName('check').dependsOn 'checkstyle'

        project.extensions.getByName('android').with {
            lintOptions {
                ignore 'GoogleAppIndexingWarning', 'ContentDescription'
            }
        }

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

the project was working perfectly till yesterday when i added a compile dependencies of picasso in my app module after the gradle sync failed it show this

 Error:(11, 0) Declaring custom 'clean' task when using the standard Gradle lifecycle plugins is not allowed. 

now even if i remove picasso the error still happening Of course I did not ask the question before long research i found some solutions but didnt work like this note : an old version of my project still working normal with the same clean task but after some gardle syncs i will get this problem.

I would like to thank you in advance for your assistance

Answer 1

After so many research i found we have to just comment the line of clean task in bulid.gradle(Project) like below :

   //    task clean(type: Delete) {
        //        delete rootProject.buildDir
        //    }][1]