Q: Gradle parallel build error in non-parallel build I have following build.gradle file:
buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:1.2.2.RELEASE")
    }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'idea'
apply plugin: 'spring-boot'

jar {
    baseName = 'mt-spring-mvc-helloworld'
    version =  '0.1.0'
}

repositories {
    mavenCentral()
}

sourceCompatibility = 1.7
targetCompatibility = 1.7

dependencies {
    compile("org.springframework.boot:spring-boot-starter-thymeleaf")
    testCompile("junit:junit:4.11")
}

task wrapper(type: Wrapper) {
    gradleVersion = '2.3'
}

Also I have simple source files under src directory. When I run gradle build, build fails and following exception is shown:
It is currently in use by another Gradle instance. What may cause this problem? I don't remember any parallel-related configuration I made to gradle. 

A: I fixed the problem. I'm using Intellij IDEA, apparently I bootRun the app before and forgot about it. After stopping the bootRun, I managed to build the code.  
