每次我尝试运行我的项目，清理它或构建它，我得到一个gradle错误：

Error:FAILURE: Build failed with an exception.
* What went wrong:
Task 'compile' is ambiguous in root project 'FifiFun2'. Candidates are: 'compileDebugAidl', 'compileDebugAndroidTestAidl', 'compileDebugAndroidTestJavaWithJavac', 'compileDebugAndroidTestNdk', 'compileDebugAndroidTestRenderscript', 'compileDebugAndroidTestSources', 'compileDebugJavaWithJavac', 'compileDebugNdk', 'compileDebugRenderscript', 'compileDebugSources', 'compileDebugUnitTestJavaWithJavac', 'compileDebugUnitTestSources', 'compileLint', 'compileReleaseAidl', 'compileReleaseJavaWithJavac', 'compileReleaseNdk', 'compileReleaseRenderscript', 'compileReleaseSources', 'compileReleaseUnitTestJavaWithJavac', 'compileReleaseUnitTestSources'.
* Try:
Run gradle tasks to get a list of available tasks. Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

我试过用上面的选项（stacktrace，info，debug）运行gradle任务，但没有任何有用的结果。
Gradler公司：

// 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:1.3.0'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}
allprojects {
    repositories {
        jcenter()
    }
}
task clean(type: Delete) {
    delete rootProject.buildDir
}

主Gradle文件：

apply plugin: 'com.android.application'
android {
    compileSdkVersion 23
    buildToolsVersion "23.0.1"
    defaultConfig {
        applicationId "com.example.user_pc.myapplication"
        minSdkVersion 19
        targetSdkVersion 23
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}
dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:23.0.1'
}

设置.gradle文件：

include ':app'

问题截图：