当我第一次运行npm install时，模块已正确安装，并且我的应用程序运行正常。但是当我运行npm时，几乎所有模块都被删除了。
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npm timing action:extract Completed in 10689ms
npm info lifecycle camelcase@4.1.0~preuninstall: camelcase@4.1.0
npm info lifecycle camelcase@4.1.0~uninstall: camelcase@4.1.0
npm verb unbuild rmStuff camelcase@4.1.0 from /var/lib/jenkins/workspace/node_modules
npm verb unbuild rmStuff in /var/lib/jenkins/workspace/node_modules/yargs/node_modules
npm info lifecycle camelcase@4.1.0~postuninstall: camelcase@4.1.0
npm info lifecycle glob@7.1.3~preuninstall: glob@7.1.3
npm info lifecycle glob@7.1.3~uninstall: glob@7.1.3
npm verb unbuild rmStuff glob@7.1.3 from /var/lib/jenkins/workspace/node_modules
npm verb unbuild rmStuff in /var/lib/jenkins/workspace/node_modules/workbox-build/node_modules
npm info lifecycle glob@7.1.3~postuninstall: glob@7.1.3
npm info lifecycle extend-shallow@3.0.2~preuninstall: extend-shallow@3.0.2
npm info lifecycle extend-shallow@3.0.2~uninstall: extend-shallow@3.0.2
npm verb unbuild rmStuff extend-shallow@3.0.2 from /var/lib/jenkins/workspace/node_modules
npm verb unbuild rmStuff in /var/lib/jenkins/workspace/node_modules/webpack/node_modules
npm info lifecycle extend-shallow@3.0.2~postuninstall: extend-shallow@3.0.2
npm info lifecycle is-extendable@1.0.1~preuninstall: is-extendable@1.0.1
npm info lifecycle is-extendable@1.0.1~uninstall: is-extendable@1.0.1
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仅供参考，我项目中的node_modules文件夹是到位于项目外部的另一个node_modules文件夹的软链接。
节点版本：v10.12.0
NPM版本：6.4.1
请帮助我找出原因。