有个项目在mac下开发，安装包npm i，一切正常；
把这个项目放到linux机器上，安装包npm i，报了一堆warning：
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@^1.2.7 (node_modules/chokidar/node_modules/fsevents): npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for [email protected]: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"}) npm WARN [email protected] No description npm WARN [email protected] No repository field. npm WARN optional SKIPPING OPTIONAL DEPENDENCY: [email protected] (node_modules/fsevents/node_modules/abbrev): npm WARN enoent SKIPPING OPTIONAL DEPENDENCY: ENOENT: no such file or directory, rename '/root/2019/0403/node_modules/fsevents/node_modules/abbrev' -> '/root/2019/0403/node_modules/fsevents/node_modules/.abbrev.DELETE' npm WARN optional SKIPPING OPTIONAL DEPENDENCY: [email protected] (node_modules/fsevents/node_modules/ansi-regex): npm WARN enoent SKIPPING OPTIONAL DEPENDENCY: ENOENT: no such file or directory, rename '/root/2019/0403/node_modules/fsevents/node_modules/ansi-regex' -> '/root/2019/0403/node_modules/fsevents/node_modules/.ansi-regex.DELETE' npm WARN optional SKIPPING OPTIONAL DEPENDENCY: [email protected] (node_modules/fsevents/node_modules/aproba): npm WARN enoent SKIPPING OPTIONAL DEPENDENCY: ENOENT: no such file or directory, rename '/root/2019/0403/node_modules/fsevents/node_modules/aproba' -> '/root/2019/0403/node_modules/fsevents/node_modules/.aproba.DELETE' npm WARN optional SKIPPING OPTIONAL DEPENDENCY: [email protected] (node_modules/fsevents/node_modules/balanced-match): npm WARN enoent SKIPPING OPTIONAL DEPENDENCY: ENOENT: no such file or directory, rename '/root/2019/0403/node_modules/fsevents/node_modules/balanced-match' -> '/root/2019/0403/node_modules/fsevents/node_modules/.balanced-match.DELETE' npm WARN optional SKIPPING OPTIONAL DEPENDENCY: [email protected] (node_modules/fsevents/node_modules/chownr): npm WARN enoent SKIPPING OPTIONAL DEPENDENCY: ENOENT: no such file or directory, rename '/root/2019/0403/node_modules/fsevents/node_modules/chownr' -> '/root/2019/0403/node_modules/fsevents/node_modules/.chownr.DELETE' npm WARN optional SKIPPING OPTIONAL DEPENDENCY: [email protected] (node_modules/fsevents/node_modules/code-point-at): npm WARN enoent SKIPPING OPTIONAL DEPENDENCY: ENOENT: no such file or directory, rename '/root/2019/0403/node_modules/fsevents/node_modules/code-point-at' -> '/root/2019/0403/node_modules/fsevents/node_modules/.code-point-at.DELETE' ...
执行npm ls，有不少UNMET OPTIONAL DEPENDENCY的模块，最后还报了一堆错：
│ ├── [email protected] deduped │ ├── [email protected] deduped │ ├── [email protected] deduped │ └─┬ [email protected] │ └── [email protected] ├─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ ├── [email protected] │ └─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ ├─┬ UNMET DEPENDENCY [email protected] │ │ └── UNMET DEPENDENCY [email protected] │ ├─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ ├─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ └── UNMET OPTIONAL DEPENDENCY [email protected] │ │ ├─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ └── UNMET OPTIONAL DEPENDENCY [email protected] │ │ └── UNMET OPTIONAL DEPENDENCY [email protected] │ ├─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ │ └─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ │ └── UNMET OPTIONAL DEPENDENCY [email protected] │ ├─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ ├─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ └─┬ UNMET DEPENDENCY [email protected] │ │ │ └─┬ UNMET DEPENDENCY [email protected] │ │ │ ├── UNMET DEPENDENCY [email protected] │ │ │ └── UNMET DEPENDENCY [email protected] │ │ └── UNMET OPTIONAL DEPENDENCY [email protected] │ ├─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ ├─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ └─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ ├── UNMET DEPENDENCY [email protected] │ │ │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ ├── UNMET DEPENDENCY [email protected] │ │ │ ├─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ │ └── UNMET DEPENDENCY [email protected] │ │ │ └── UNMET OPTIONAL DEPENDENCY [email protected] │ │ ├── UNMET DEPENDENCY [email protected] │ │ ├─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ ├── UNMET DEPENDENCY [email protected] │ │ │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ ├─┬ UNMET DEPENDENCY [email protected] │ │ │ │ ├── UNMET DEPENDENCY [email protected] │ │ │ │ ├─┬ UNMET DEPENDENCY [email protected] │ │ │ │ │ └── UNMET DEPENDENCY [email protected] │ │ │ │ └── UNMET DEPENDENCY [email protected] │ │ │ ├─┬ UNMET DEPENDENCY [email protected] │ │ │ │ └── UNMET DEPENDENCY [email protected] │ │ │ └─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ └── UNMET DEPENDENCY [email protected] │ │ └── UNMET OPTIONAL DEPENDENCY [email protected] │ ├─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ │ └── UNMET OPTIONAL DEPENDENCY [email protected] │ ├─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ └─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ │ ├─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ │ ├── UNMET DEPENDENCY [email protected] │ │ │ └── UNMET DEPENDENCY [email protected] │ │ ├── UNMET DEPENDENCY [email protected] │ │ ├── UNMET DEPENDENCY [email protected] │ │ ├─┬ UNMET DEPENDENCY [email protected] │ │ │ └── UNMET DEPENDENCY [email protected] │ │ └── UNMET OPTIONAL DEPENDENCY [email protected] │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ └─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ ├── UNMET OPTIONAL DEPENDENCY [email protected] │ ├─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ └── UNMET DEPENDENCY [email protected] │ ├─┬ UNMET DEPENDENCY [email protected] │ │ ├── UNMET DEPENDENCY [email protected] │ │ └── UNMET DEPENDENCY [email protected] │ ├─┬ UNMET OPTIONAL DEPENDENCY [email protected] │ │ └── UNMET DEPENDENCY [email protected] │ ├── UNMET DEPENDENCY [email protected] │ ├── UNMET DEPENDENCY [email protected] │ └── UNMET DEPENDENCY [email protected] ├─┬ [email protected] │ ├─┬ [email protected] │ │ └── [email protected] deduped │ └── [email protected] ├── [email protected] ├─┬ [email protected] │ └── [email protected] ├─┬ [email protected] │ └── [email protected] ├── [email protected] ├── [email protected] ├─┬ [email protected] │ ├── [email protected] │ ├── [email protected] deduped │ └─┬ [email protected] │ ├── [email protected] │ ├── [email protected] deduped │ ├── [email protected] │ ├── [email protected] │ ├── [email protected] │ ├─┬ [email protected] │ │ └── [email protected] deduped │ └── [email protected] └── [email protected]
npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected] npm ERR! missing: [email protected], required by [email protected]
仔细观察发现UNMET OPTIONAL DEPENDENCY的模块和npm ERR是同一批模块，也是安装时报warning的那些模块。
再仔细观察发现这些都是fsevents依赖的模块。
fsevents只能在macOS下安装，无法在linux系统安装。linux下会跳过fsevents模块，也不会安装fsevents依赖的模块。
这其实算是npm的一个bug，npm i时报Warn，npm ls又报Err，前后不一致，容易有误解。
目前无论用哪个版本的npm都会有这个问题，npm i --no-optional也不能解决这个问题。
这些报错不影响项目的正常运行，因为linux不需要fsevents。
如果不希望看到npm Err，可以用npm i -f强制安装，安装过程没有warn，安装完后npm ls看下：
└─┬ [email protected] └── [email protected]
干净了，没有任何报错。
我的项目是chokidar这个模块依赖了fsevents，chokidar又是browser-sync、webpack等依赖的。
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。