npm install 的 lock 文件是什么情况?

全局安装模块的时候, 进度就卡在这里了. 这个 lock 是什么?

npm http fetch GET 304 https://registry.npmjs.org/is-buffer 161ms (from cache)
npm http fetch GET 304 https://registry.npmjs.org/batch 156ms (from cache)
npm http fetch GET 304 https://registry.npmjs.org/async-limiter 139ms (from cache)
npm verb correctMkdir /Users/chen/.npm/_locks correctMkdir not in flight; initializing
npm verb makeDirectory /Users/chen/.npm/_locks creation not in flight; initializing
npm verb lock using /Users/chen/.npm/_locks/staging-3a08f0df5026584d.lock for /usr/local/lib/node_modules/.staging
⸨            ░░░░░░⸩ ⠇ extract:lodash: sill extract [email protected]

先换 yarn 把事情干了…