在@Sean Stayns的回答中引用了一个场景，以防它能帮助到任何人:如果你把你的项目保存在谷歌Drive文件夹中——不要这样做。只需将项目移动到本地驱动器即可解决此问题。

In the case we were trying to solve, were were also getting the "It is currently in use by another Gradle instance" error and nothing we tried here worked. The process ID was unknown as well. It didn't immediately occur to me to ask where the project was being saved, so in case anyone new to Android Dev is saving their projects to a Google Drive folder, just move over to your local drive. I would have just left this as a comment in @Sean Stayns's answer, but I can't comment. Hopefully it benefits someone.

我被这个错误所困扰，不得不删除用户的.gradle/caches/文件夹的内容和项目的.gradle/文件夹的内容才能继续运行。

不知道是什么引起的，可能是一个失败的构建，使这些文件处于锁定状态?

这些答案我都试过了，包括杀死java进程，在HOME_DIR和project dir中删除.gradle，重启Android Studio，甚至重启OS。

它开始正常工作后，我启动gradle同步。

通过执行如下命令删除gradle缓存中的锁文件:

find ~/.gradle -type f -name "*.lock" -delete

在Mac上遇到同样的问题时，以上这些方法对我都不起作用。但是，有效的方法是打开活动监视器并关闭正在运行的java进程。我还注意到生成了一个.hprof文件，我删除了它。在那之后，我运行了我的项目，它成功了。

打开终端，移动到项目路径，然后根据操作系统运行: Gradlew clean或。/ Gradlew clean