groovy - Gradle任务永远不会是最新的

Question

在任务的配置阶段，我将一些目录注册为builtBy: thisTask。我希望gradle能够自动检测源是否已更改，但是任务总是在执行。
这是任务:

subprojects {

    def srcMainMirah = file('src/main/mirah')
    if (srcMainMirah.exists()) {

        idea.module.sourceDirs += srcMainMirah

        task compileMirah {

            def classesMirahMain = file("$buildDir/classes-mirah/main")

            inputs.sourceDir srcMainMirah
            def thisTask = delegate
            sourceSets.main {
                output.dir(classesMirahMain, builtBy: thisTask)
                java.srcDir srcMainMirah
            }
            dependsOn tasks.compileJava

            doFirst {
                def classpath = files("$buildDir/classes/main").plus(configurations.compile)
                mirahc(srcMainMirah, classesMirahMain, classpath)
            }
        }
    }
}

它用于以mirah语言编译源代码，就像Java编译器一样，它会生成*.class文件。

Answer 1

仅声明任务的输入不足以确定任务是否最新。您还必须声明task.outputs

A task with no defined outputs will never be considered up-to-date. For scenarios where the outputs of a task are not files, or for more complex scenarios, the TaskOutputs.upToDateWhen() method allows you to calculate programmatically if the tasks outputs should be considered up to date.

A task with only outputs defined will be considered up-to-date if those outputs are unchanged since the previous build.

从section 17.9.1 here。