解决flutter 运行时：Waiting for another flutter command to release the startup lock...

执行 Flutter 包管理相关命令时有可能遇到 Waiting for another flutter command to release the startup lock... 这样的错误，可尝试杀死所有的 dart 进程解决：

// Linux
killall -9 dart

// Windows
taskkill /F /IM dart.exe

亦可通过删除 flutter 安装目录下的 bin/cache/lockfile 文件解决

参考：https://zhuanlan.zhihu.com/p/113223263