升级Gradle与Android Gradle Plugin至8.x后无法发布Android库

问题场景 #

原项目使用Gradle 7.6.1 + Android Gradle Plugin(AGP) 7.4.2，发布相关配置如下：

plugins {
    id("com.android.library")
    id("maven-publish")
}

task generateSourcesJar(type: Jar) {
    from android.sourceSets.main.java.srcDirs
    archiveClassifier.set("sources")
}

afterEvaluate {
    publishing {
        publications {
            release(MavenPublication) {
                from components.release
                artifact generateSourcesJar

                groupId "com.tazkiyatech"
                artifactId "android-utils"
                version "1.0.0"
            }
        }

        repositories {
            maven {
                name = "BuildFolder"
                url = "${project.buildDir}/repository"
            }
        }
    }
}

升级至Gradle 8.x + AGP 8.x后，执行publish系列任务时触发报错：

• What went wrong:
  A problem was found with the configuration of task ':library:generateSourcesJar' (type 'Jar').

  • Gradle detected a problem with the following location: '/Users/adil/Work/TazkiyaTech/android-utils/library/build/libs/library-sources.jar'.

    Reason: Task ':library:generateMetadataFileForReleasePublication' uses this output of task ':library:generateSourcesJar' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed.

    Possible solutions:

    1. Declare task ':library:generateSourcesJar' as an input of ':library:generateMetadataFileForReleasePublication'.
    2. Declare an explicit dependency on ':library:generateSourcesJar' from ':library:generateMetadataFileForReleasePublication' using Task#dependsOn.
    3. Declare an explicit dependency on ':library:generateSourcesJar' from ':library:generateMetadataFileForReleasePublication' using Task#mustRunAfter.

解决方案 #

只需在afterEvaluate块中，给自动生成的metadata任务添加对generateSourcesJar的显式依赖即可，修改后的完整配置如下：

plugins {
    id("com.android.library")
    id("maven-publish")
}

task generateSourcesJar(type: Jar) {
    from android.sourceSets.main.java.srcDirs
    archiveClassifier.set("sources")
}

afterEvaluate {
    // 给自动生成的metadata任务添加显式依赖
    tasks.named("generateMetadataFileForReleasePublication") {
        dependsOn(generateSourcesJar)
    }

    publishing {
        publications {
            release(MavenPublication) {
                from components.release
                artifact generateSourcesJar

                groupId "com.tazkiyatech"
                artifactId "android-utils"
                version "1.0.0"
            }
        }

        repositories {
            maven {
                name = "BuildFolder"
                url = "${project.buildDir}/repository"
            }
        }
    }
}

补充说明 #

Gradle 8.x对任务依赖的校验更为严格，不再允许隐式依赖存在。通过tasks.named()可以定位到publishing插件自动生成的generateMetadataFileForReleasePublication任务，再用dependsOn声明它必须在generateSourcesJar执行完成后再运行，即可解决依赖缺失的问题。

内容的提问来源于stack exchange，提问作者Adil Hussain