Android Studio 3.5用于启动仿真器，该仿真器在MacOS 10.14上运行我的项目时直观地出现。现在，无论我是通过CLI（$ emulator @Nexus_6_API_28 -verbose）还是GUI（在Android Studio中单击AVD Manager中的绿色“播放”按钮）手动启动仿真器，还是在运行项目时自动生成该仿真器，我看到的只是一个蓝色文件夹图标出现在我的MacOS扩展坞底部，标签为“模拟器”。否则，屏幕上什么也不会出现（即，没有电话外观的GUI）。

我已经卸载了Android Studio，然后重新安装了几次。最近一次，我使用AppCleaner删除了它，然后手动删除了~/.android和/Users/hamx0r/library/Android文件夹。重新安装后，将重新创建这些文件夹，并且我必须下载SDK套件，仿真器等，以确保它们处于默认配置且是最新的。现在，不仅不显示模拟器，而且当我尝试构建项目时，gradle会引发错误Unable to acquire a file lock for /Users/hamx0r/.android/debug.keystore.lock。如果我检查该文件，则它具有rwxrwxrwx权限，因此显然可以访问。如果再看一些回溯，我会看到：

org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:validateSigningDebug'.
    at org.gradle.api.internal.tasks.execution.ExecuteactionsTaskExecuter$3.accept(ExecuteactionsTaskExecuter.java:151)
    at org.gradle.api.internal.tasks.execution.ExecuteactionsTaskExecuter$3.accept(ExecuteactionsTaskExecuter.java:148)
    at org.gradle.internal.Try$Failure.ifSuccessfulOrElse(Try.java:191)
    at org.gradle.api.internal.tasks.execution.ExecuteactionsTaskExecuter.execute(ExecuteactionsTaskExecuter.java:141)
    at org.gradle.api.internal.tasks.execution.ResolveBeforeExecutionstatetaskExecuter.execute(ResolveBeforeExecutionstatetaskExecuter.java:75)
    at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:62)
    at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:108)
    at org.gradle.api.internal.tasks.execution.ResolveBeforeExecutionOutputsTaskExecuter.execute(ResolveBeforeExecutionOutputsTaskExecuter.java:67)
    at org.gradle.api.internal.tasks.execution.ResolveAfterPreviousExecutionstatetaskExecuter.execute(ResolveAfterPreviousExecutionstatetaskExecuter.java:46)
    at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:94)
    at org.gradle.api.internal.tasks.execution.FinalizePropertiesTaskExecuter.execute(FinalizePropertiesTaskExecuter.java:46)
    at org.gradle.api.internal.tasks.execution.ResolvetaskExecutionmodeExecuter.execute(ResolvetaskExecutionmodeExecuter.java:95)
    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:73)
    at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:52)
    at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:49)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:416)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:406)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:165)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:102)
    at org.gradle.internal.operations.DelegatingBuildOperationExecutor.call(DelegatingBuildOperationExecutor.java:36)
    at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:49)
    at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:43)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsaction.execute(DefaultTaskExecutionGraph.java:355)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsaction.execute(DefaultTaskExecutionGraph.java:343)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionaction.execute(DefaultTaskExecutionGraph.java:336)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionaction.execute(DefaultTaskExecutionGraph.java:322)
    at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker$1.execute(DefaultPlanExecutor.java:134)
    at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker$1.execute(DefaultPlanExecutor.java:129)
    at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:202)
    at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.executeNextNode(DefaultPlanExecutor.java:193)
    at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:129)
    at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
    at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.RuntimeException: Unable to acquire a file lock for /Users/hamx0r/.android/debug.keystore.lock
    at com.android.utils.concurrency.ReadWriteProcessLock.acquireFileLock(ReadWriteProcessLock.java:482)
    at com.android.utils.concurrency.ReadWriteProcessLock.acquireInterProcessLock(ReadWriteProcessLock.java:367)
    at com.android.utils.concurrency.ReadWriteProcessLock.acquireLock(ReadWriteProcessLock.java:292)

使用谷歌搜索此错误不会产生任何结果，而使用谷歌搜索为什么模拟器不显示只会导致4年前的两个未解决的SO问题。有见识吗？