title: unexpected markup <!d (position: START_DOCUMENT seen \n<!d... @2:4)
body: <p>I'm tryin to publish my Gradle projects on maven, via <code>maven-publish</code> plugin.</p>
  
  <p>I set my Gradle script as follow
  <code>build.gradle.kts</code></p>
  
  <pre class="lang-kotlin prettyprint-override"><code>apply&lt;MavenPublishPlugin&gt;()
  
  publishing {
    publications.withType&lt;MavenPublication&gt; {
  
      artifact(javaDocsJar)
      artifact(sourcesJar)
  
      pom {
        name.set(c.name)
        description.set(c.description)
        url.set(c.siteUrl)
        scm {
          url.set(c.scmUrl)
          connection.set("scm:git:${c.scmConnection}")
          developerConnection.set("scm:git:${c.scmDevConnection}")
        }
      }
    }
    repositories {
      val target = c.organization.takeIf { it.isNotBlank() } ?: c.username
      maven("https://bintray.com/$target/${c.repo}/") {
        credentials {
          username = c.username
          password = c.apiKey
        }
      }
    }
  }
  </code></pre>
  
  <p>After this I run <code>./gradlew publish</code>, and it starts to upload jars/aar/pom etc, but when it comes to <strong>maven-metadata.xml</strong> I got the following exception.</p>
  
  <p>I tried on a Kotlin multiplatform project, on a java one ( mixed plain java/kotlin modules and Android ), on Android Studio 4.0, on IntelliJ Ultimate 2020.1.1, on JDK 1.8, on JDK 14, with plain <code>maven-publish</code> plugin and with <a href="https://github.com/vanniktech/gradle-maven-publish-plugin" rel="nofollow noreferrer">this plugin</a>. I really don't know what to try.
  I already tried to exclude maven and plexus packages from Robolectric implementation, which is often problematic...</p>
  
  <p><a href="https://github.com/4face-studi0/Assert4K" rel="nofollow noreferrer"><strong>Kotlin multiplatform project here!</strong></a></p>
  
  <pre><code>* What went wrong:
  Execution failed for task ':publishPluginMavenPublicationToMavenRepository'.
  &gt; Failed to publish publication 'pluginMaven' to repository 'maven'
     &gt; org.codehaus.plexus.util.xml.pull.XmlPullParserException: unexpected markup &lt;!d (position: START_DOCUMENT seen \n&lt;!d... @2:4) 
  
  * Try:
  Run with --info or --debug option to get more log output. Run with --scan to get full insights.
  
  * Exception is:
  org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':util:util-gradle:publishPluginMavenPublicationToMavenRepository'.
          at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.lambda$executeIfValid$1(ExecuteActionsTaskExecuter.java:205)
          at org.gradle.internal.Try$Failure.ifSuccessfulOrElse(Try.java:263)
          at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeIfValid(ExecuteActionsTaskExecuter.java:203)
          at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:184)
          at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:114)
          at org.gradle.api.internal.tasks.execution.FinalizePropertiesTaskExecuter.execute(FinalizePropertiesTaskExecuter.java:46)
          at org.gradle.api.internal.tasks.execution.ResolveTaskExecutionModeExecuter.execute(ResolveTaskExecutionModeExecuter.java:62)
          at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:57)
          at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:56)
          at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:36)
          at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.executeTask(EventFiringTaskExecuter.java:77)
          at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:55)
          at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:52)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:416)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:406)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:165)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:102)
          at org.gradle.internal.operations.DelegatingBuildOperationExecutor.call(DelegatingBuildOperationExecutor.java:36)
          at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:52)
          at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:41)
          at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:372)
          at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:359)
          at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:352)
          at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:338)
          at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.lambda$run$0(DefaultPlanExecutor.java:127)
          at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:191)
          at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.executeNextNode(DefaultPlanExecutor.java:182)
          at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:124)
          at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
          at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:48)
          at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
  Caused by: org.gradle.api.artifacts.PublishException: Failed to publish publication 'pluginMaven' to repository 'maven'
          at org.gradle.api.publish.internal.PublishOperation.run(PublishOperation.java:39)
          at org.gradle.api.publish.maven.tasks.PublishToMavenRepository.doPublish(PublishToMavenRepository.java:79)
          at org.gradle.api.publish.maven.tasks.PublishToMavenRepository.publish(PublishToMavenRepository.java:68)
          at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:104)
          at org.gradle.api.internal.project.taskfactory.StandardTaskAction.doExecute(StandardTaskAction.java:49)
          at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:42)
          at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:28)
          at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:727)
          at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:694)
          at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$3.run(ExecuteActionsTaskExecuter.java:568)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:402)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:394)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:165)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:92)
          at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31)
          at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:553)
          at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:536)
          at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.access$300(ExecuteActionsTaskExecuter.java:109)
          at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$TaskExecution.executeWithPreviousOutputFiles(ExecuteActionsTaskExecuter.java:276)
          at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$TaskExecution.execute(ExecuteActionsTaskExecuter.java:265)
          at org.gradle.internal.execution.steps.ExecuteStep.lambda$execute$1(ExecuteStep.java:33)
          at org.gradle.internal.execution.steps.ExecuteStep.execute(ExecuteStep.java:33)
          at org.gradle.internal.execution.steps.ExecuteStep.execute(ExecuteStep.java:26)
          at org.gradle.internal.execution.steps.CleanupOutputsStep.execute(CleanupOutputsStep.java:67)
          at org.gradle.internal.execution.steps.CleanupOutputsStep.execute(CleanupOutputsStep.java:36)
          at org.gradle.internal.execution.steps.ResolveInputChangesStep.execute(ResolveInputChangesStep.java:49)
          at org.gradle.internal.execution.steps.ResolveInputChangesStep.execute(ResolveInputChangesStep.java:34)
          at org.gradle.internal.execution.steps.CancelExecutionStep.execute(CancelExecutionStep.java:43)
          at org.gradle.internal.execution.steps.TimeoutStep.executeWithoutTimeout(TimeoutStep.java:73)
          at org.gradle.internal.execution.steps.TimeoutStep.execute(TimeoutStep.java:54)
          at org.gradle.internal.execution.steps.CatchExceptionStep.execute(CatchExceptionStep.java:34)
          at org.gradle.internal.execution.steps.CreateOutputsStep.execute(CreateOutputsStep.java:44)
          at org.gradle.internal.execution.steps.SnapshotOutputsStep.execute(SnapshotOutputsStep.java:54)
          at org.gradle.internal.execution.steps.SnapshotOutputsStep.execute(SnapshotOutputsStep.java:38)
          at org.gradle.internal.execution.steps.BroadcastChangingOutputsStep.execute(BroadcastChangingOutputsStep.java:49)
          at org.gradle.internal.execution.steps.CacheStep.executeWithoutCache(CacheStep.java:159)
          at org.gradle.internal.execution.steps.CacheStep.execute(CacheStep.java:72)
          at org.gradle.internal.execution.steps.CacheStep.execute(CacheStep.java:43)
          at org.gradle.internal.execution.steps.StoreExecutionStateStep.execute(StoreExecutionStateStep.java:44)
          at org.gradle.internal.execution.steps.StoreExecutionStateStep.execute(StoreExecutionStateStep.java:33)
          at org.gradle.internal.execution.steps.RecordOutputsStep.execute(RecordOutputsStep.java:38)
          at org.gradle.internal.execution.steps.RecordOutputsStep.execute(RecordOutputsStep.java:24)
          at org.gradle.internal.execution.steps.SkipUpToDateStep.executeBecause(SkipUpToDateStep.java:92)
          at org.gradle.internal.execution.steps.SkipUpToDateStep.lambda$execute$0(SkipUpToDateStep.java:85)
          at org.gradle.internal.execution.steps.SkipUpToDateStep.execute(SkipUpToDateStep.java:55)
          at org.gradle.internal.execution.steps.SkipUpToDateStep.execute(SkipUpToDateStep.java:39)
          at org.gradle.internal.execution.steps.ResolveChangesStep.execute(ResolveChangesStep.java:76)
          at org.gradle.internal.execution.steps.ResolveChangesStep.execute(ResolveChangesStep.java:37)
          at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsFinishedStep.execute(MarkSnapshottingInputsFinishedStep.java:36)
          at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsFinishedStep.execute(MarkSnapshottingInputsFinishedStep.java:26)
          at org.gradle.internal.execution.steps.ResolveCachingStateStep.execute(ResolveCachingStateStep.java:94)
          at org.gradle.internal.execution.steps.ResolveCachingStateStep.execute(ResolveCachingStateStep.java:49)
          at org.gradle.internal.execution.steps.CaptureStateBeforeExecutionStep.execute(CaptureStateBeforeExecutionStep.java:79)
          at org.gradle.internal.execution.steps.CaptureStateBeforeExecutionStep.execute(CaptureStateBeforeExecutionStep.java:53)
          at org.gradle.internal.execution.steps.ValidateStep.execute(ValidateStep.java:74)
          at org.gradle.internal.execution.steps.SkipEmptyWorkStep.lambda$execute$2(SkipEmptyWorkStep.java:78)
          at org.gradle.internal.execution.steps.SkipEmptyWorkStep.execute(SkipEmptyWorkStep.java:78)
          at org.gradle.internal.execution.steps.SkipEmptyWorkStep.execute(SkipEmptyWorkStep.java:34)
          at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsStartedStep.execute(MarkSnapshottingInputsStartedStep.java:39)
          at org.gradle.internal.execution.steps.LoadExecutionStateStep.execute(LoadExecutionStateStep.java:40)
          at org.gradle.internal.execution.steps.LoadExecutionStateStep.execute(LoadExecutionStateStep.java:28)
          at org.gradle.internal.execution.impl.DefaultWorkExecutor.execute(DefaultWorkExecutor.java:33)
          at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeIfValid(ExecuteActionsTaskExecuter.java:192)
          ... 30 more
  Caused by: org.gradle.internal.UncheckedException: org.codehaus.plexus.util.xml.pull.XmlPullParserException: unexpected markup &lt;!d (position: START_DOCUMENT seen \n&lt;!d... @2:4) 
          at org.gradle.internal.UncheckedException.throwAsUncheckedException(UncheckedException.java:67)
          at org.gradle.internal.UncheckedException.throwAsUncheckedException(UncheckedException.java:41)
          at org.gradle.api.publish.maven.internal.publisher.AbstractMavenPublisher.lambda$readExistingMetadata$1(AbstractMavenPublisher.java:139)
          at org.gradle.internal.resource.transfer.AccessorBackedExternalResource.withContentIfPresent(AccessorBackedExternalResource.java:113)
          at org.gradle.internal.resource.BuildOperationFiringExternalResourceDecorator$10.call(BuildOperationFiringExternalResourceDecorator.java:221)
          at org.gradle.internal.resource.BuildOperationFiringExternalResourceDecorator$10.call(BuildOperationFiringExternalResourceDecorator.java:213)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:416)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:406)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:165)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158)
          at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:102)
          at org.gradle.internal.operations.DelegatingBuildOperationExecutor.call(DelegatingBuildOperationExecutor.java:36)
          at org.gradle.internal.resource.BuildOperationFiringExternalResourceDecorator.withContentIfPresent(BuildOperationFiringExternalResourceDecorator.java:213)
          at org.gradle.api.publish.maven.internal.publisher.AbstractMavenPublisher.readExistingMetadata(AbstractMavenPublisher.java:135)
          at org.gradle.api.publish.maven.internal.publisher.AbstractMavenPublisher.getExistingVersioning(AbstractMavenPublisher.java:111)
          at org.gradle.api.publish.maven.internal.publisher.AbstractMavenPublisher.createMetadata(AbstractMavenPublisher.java:93)
          at org.gradle.api.publish.maven.internal.publisher.AbstractMavenPublisher.publish(AbstractMavenPublisher.java:88)
          at org.gradle.api.publish.maven.internal.publisher.MavenRemotePublisher.publish(MavenRemotePublisher.java:62)
          at org.gradle.api.publish.maven.internal.publisher.ValidatingMavenPublisher.publish(ValidatingMavenPublisher.java:50)
          at org.gradle.api.publish.maven.tasks.PublishToMavenRepository$1.publish(PublishToMavenRepository.java:77)
          at org.gradle.api.publish.internal.PublishOperation.run(PublishOperation.java:37)
          ... 94 more
  Caused by: org.codehaus.plexus.util.xml.pull.XmlPullParserException: unexpected markup &lt;!d (position: START_DOCUMENT seen \n&lt;!d... @2:4) 
          at org.codehaus.plexus.util.xml.pull.MXParser.parseProlog(MXParser.java:1790)
          at org.codehaus.plexus.util.xml.pull.MXParser.nextImpl(MXParser.java:1698)
          at org.codehaus.plexus.util.xml.pull.MXParser.next(MXParser.java:1317)
          at org.apache.maven.artifact.repository.metadata.io.xpp3.MetadataXpp3Reader.read(MetadataXpp3Reader.java:1193)
          at org.apache.maven.artifact.repository.metadata.io.xpp3.MetadataXpp3Reader.read(MetadataXpp3Reader.java:1122)
          at org.apache.maven.artifact.repository.metadata.io.xpp3.MetadataXpp3Reader.read(MetadataXpp3Reader.java:1151)
          at org.gradle.api.publish.maven.internal.publisher.AbstractMavenPublisher.lambda$readExistingMetadata$1(AbstractMavenPublisher.java:137)
          ... 113 more
  
  </code></pre>