使用Gradle构建的Android项目在Jenkins上失败

Question

我正在尝试使用Jenkins和Gradle构建一个Android项目。在compileUnitTestJava任务中构建失败，没有找到测试中导入的任何类。在Android Studio中，运行测试没有问题，但在Jenkins上，构建失败。

项目中包含的测试如下：

package mobile_teacher.test;

import android.content.Intent;
import android.test.ActivityUnitTestCase;

import mobile_teacher.R;
import mobile_teacher.src.DashboardActivity;

/**
 * Created by blavi on 6/2/14.
 */
public class DashboardTest extends ActivityUnitTestCase<DashboardActivity> {

    public DashboardActivity activity;

    public DashboardTest() {
        super(DashboardActivity.class);
    }

    @Override
    public void setUp() throws Exception {
        super.setUp();
        Intent intent = new Intent(getInstrumentation().getTargetContext(),
                DashboardActivity.class);
        startActivity(intent, null, null);
        activity = getActivity();
    }

    public void testLayout(){
        assertNotNull(activity.findViewById(R.id.lessonsList));
    }
}

build.gradle是：

 android {
    compileSdkVersion 19
    buildToolsVersion '19.1.0'

    defaultConfig {
        minSdkVersion 9
        targetSdkVersion 19
    }

    sourceSets {
        main {
            manifest.srcFile 'src/main/AndroidManifest.xml'
            java.srcDirs = ['src']
            resources.srcDirs = ['src']
            aidl.srcDirs = ['src']
            renderscript.srcDirs = ['src']
            res.srcDirs = ['src/main/res']
        }
    }

    lintOptions {
        abortOnError false
    }
}
    // extend the runtime
    configurations {
        unitTestCompile.extendsFrom runtime
        unitTestRuntime.extendsFrom unitTestCompile
    }

    dependencies {
        compile files('libs/libGoogleAnalyticsServices.jar')
        compile 'com.android.support:appcompat-v7:19.0.0'
        compile 'com.google.android.gms:play-services:4.3.23'

        unitTestCompile files("$project.buildDir/classes/release")
        unitTestCompile 'junit:junit:4.11'
        unitTestCompile 'com.google.android:android:4.0.1.2'
        unitTestCompile 'com.google.android:android-test:4.1.1.4'
    }

    // add a new unitTest sourceSet
    sourceSets {
        unitTest {
            java.srcDir file('src/tests/java')
        }
    }

    // add the unitTest task
    task unitTest(type:Test, dependsOn: assemble) {
        description = "run unit tests"
        testClassesDir = project.sourceSets.unitTest.output.classesDir
        classpath = project.sourceSets.unitTest.runtimeClasspath
    }

    check.dependsOn unitTest