Gradle发布源代码和Javadoc JAR，但不发布源JAR

Question

我是Gradle的新手，正在尝试向Maven Central发布一个简单的项目。我的build.gradle脚本在他们的文档中为nearly identical to the example，但是没有上传我的主/编译JAR。源JAR，Javadoc JAR等可以很好地上传，但不能进行编译。

通过publishToMavenLocal发布本地时，一切正常。我会注意到我正在使用6.0.1版，并使用publishMavenJavaPublicationToMavenRepository发布到Central。

我想念什么？如何将已编译的JAR保存到Central？

更新：我刚刚意识到POM也没有被上传。

以下是完整的build.gradle：

plugins {
    id 'java-library'
    id 'maven-publish'
    id 'signing'
}

repositories {
    jcenter()
    mavenCentral()
}

dependencies {
    implementation 'com.squareup.okhttp3:okhttp:4.0.1'
    implementation 'com.squareup.moshi:moshi:1.9.1'
    implementation 'com.squareup.moshi:moshi-adapters:1.9.1'
    implementation 'com.google.guava:guava:28.0-jre'

    api 'org.apache.commons:commons-math3:3.6.1'

    testImplementation 'junit:junit:4.12'
}

group   = 'com.acme'
version = '0.0.1-SNAPSHOT'

ext.isReleaseVersion = !version.endsWith("SNAPSHOT")

java {
    withJavadocJar()
    withSourcesJar()
}

publishing {
    publications {
        mavenJava(MavenPublication) {
            artifactId = 'thttpd'
            from components.java

            pom {
                name = 'thttpd'

                licenses {
                    license {
                        name = 'The MIT License (MIT)'
                        url = 'https://opensource.org/licenses/MIT'
                    }
                }

                scm {
                    connection = 'scm:git:https://acme.com'
                    developerConnection = 'scm:git:https://acme.com'
                    url = 'https://acme.com'
                }
            }
        }
    }

    repositories {
        // Maven Central
        maven {
            def releasesRepoUrl  = 'https://oss.sonatype.org/service/local/staging/deploy/maven2/'
            def snapshotsRepoUrl = 'https://oss.sonatype.org/content/repositories/snapshots/'
            url = isReleaseVersion ? releasesRepoUrl : snapshotsRepoUrl
            credentials {
                username = nexusUsername
                password = nexusPassword
            }
        }
    }
}

signing {
    required { isReleaseVersion && gradle.taskGraph.hasTask("publish") }
    if( required ) {
        sign publishing.publications.mavenJava
    }
}