详解linux下fsevents模块引起的npm ls报错解决办法

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 fsevents@1.2.7: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
npm warn 0403@1.0.0 no description
npm warn 0403@1.0.0 no repository field.
npm warn optional skipping optional dependency: abbrev@1.1.1 (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: ansi-regex@2.1.1 (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: aproba@1.2.0 (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: balanced-match@1.0.0 (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: chownr@1.1.1 (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: code-point-at@1.1.0 (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：

│  ├── define-property@2.0.2 deduped
│  ├── extend-shallow@3.0.2 deduped
│  ├── regex-not@1.0.2 deduped
│  └─┬ safe-regex@1.1.0
│   └── ret@0.1.15
├─┬ unmet optional dependency fsevents@1.2.7
│ ├── nan@2.13.2
│ └─┬ unmet optional dependency node-pre-gyp@0.10.3
│  ├── unmet optional dependency detect-libc@1.0.3
│  ├─┬ unmet dependency mkdirp@0.5.1
│  │ └── unmet dependency minimist@0.0.8
│  ├─┬ unmet optional dependency needle@2.2.4
│  │ ├─┬ unmet optional dependency debug@2.6.9
│  │ │ └── unmet optional dependency ms@2.0.0
│  │ ├─┬ unmet optional dependency iconv-lite@0.4.24
│  │ │ └── unmet optional dependency safer-buffer@2.1.2
│  │ └── unmet optional dependency sax@1.2.4
│  ├─┬ unmet optional dependency nopt@4.0.1
│  │ ├── unmet optional dependency abbrev@1.1.1
│  │ └─┬ unmet optional dependency osenv@0.1.5
│  │  ├── unmet optional dependency os-homedir@1.0.2
│  │  └── unmet optional dependency os-tmpdir@1.0.2
│  ├─┬ unmet optional dependency npm-packlist@1.2.0
│  │ ├─┬ unmet optional dependency ignore-walk@3.0.1
│  │ │ └─┬ unmet dependency minimatch@3.0.4
│  │ │  └─┬ unmet dependency brace-expansion@1.1.11
│  │ │   ├── unmet dependency balanced-match@1.0.0
│  │ │   └── unmet dependency concat-map@0.0.1
│  │ └── unmet optional dependency npm-bundled@1.0.5
│  ├─┬ unmet optional dependency npmlog@4.1.2
│  │ ├─┬ unmet optional dependency are-we-there-yet@1.1.5
│  │ │ ├── unmet optional dependency delegates@1.0.0
│  │ │ └─┬ unmet optional dependency readable-stream@2.3.6
│  │ │  ├── unmet optional dependency core-util-is@1.0.2
│  │ │  ├── unmet dependency inherits@2.0.3
│  │ │  ├── unmet optional dependency isarray@1.0.0
│  │ │  ├── unmet optional dependency process-nextick-args@2.0.0
│  │ │  ├── unmet dependency safe-buffer@5.1.2
│  │ │  ├─┬ unmet optional dependency string_decoder@1.1.1
│  │ │  │ └── unmet dependency safe-buffer@5.1.2
│  │ │  └── unmet optional dependency util-deprecate@1.0.2
│  │ ├── unmet dependency console-control-strings@1.1.0
│  │ ├─┬ unmet optional dependency gauge@2.7.4
│  │ │ ├── unmet optional dependency aproba@1.2.0
│  │ │ ├── unmet dependency console-control-strings@1.1.0
│  │ │ ├── unmet optional dependency has-unicode@2.0.1
│  │ │ ├── unmet optional dependency object-assign@4.1.1
│  │ │ ├── unmet optional dependency signal-exit@3.0.2
│  │ │ ├─┬ unmet dependency string-width@1.0.2
│  │ │ │ ├── unmet dependency code-point-at@1.1.0
│  │ │ │ ├─┬ unmet dependency is-fullwidth-code-point@1.0.0
│  │ │ │ │ └── unmet dependency number-is-nan@1.0.1
│  │ │ │ └── unmet dependency strip-ansi@3.0.1
│  │ │ ├─┬ unmet dependency strip-ansi@3.0.1
│  │ │ │ └── unmet dependency ansi-regex@2.1.1
│  │ │ └─┬ unmet optional dependency wide-align@1.1.3
│  │ │  └── unmet dependency string-width@1.0.2
│  │ └── unmet optional dependency set-blocking@2.0.0
│  ├─┬ unmet optional dependency rc@1.2.8
│  │ ├── unmet optional dependency deep-extend@0.6.0
│  │ ├── unmet optional dependency ini@1.3.5
│  │ ├── unmet optional dependency minimist@1.2.0
│  │ └── unmet optional dependency strip-json-comments@2.0.1
│  ├─┬ unmet optional dependency rimraf@2.6.3
│  │ └─┬ unmet optional dependency glob@7.1.3
│  │  ├── unmet optional dependency fs.realpath@1.0.0
│  │  ├─┬ unmet optional dependency inflight@1.0.6
│  │  │ ├── unmet dependency once@1.4.0
│  │  │ └── unmet dependency wrappy@1.0.2
│  │  ├── unmet dependency inherits@2.0.3
│  │  ├── unmet dependency minimatch@3.0.4
│  │  ├─┬ unmet dependency once@1.4.0
│  │  │ └── unmet dependency wrappy@1.0.2
│  │  └── unmet optional dependency path-is-absolute@1.0.1
│  ├── unmet optional dependency semver@5.6.0
│  └─┬ unmet optional dependency tar@4.4.8
│   ├── unmet optional dependency chownr@1.1.1
│   ├─┬ unmet optional dependency fs-minipass@1.2.5
│   │ └── unmet dependency minipass@2.3.5
│   ├─┬ unmet dependency minipass@2.3.5
│   │ ├── unmet dependency safe-buffer@5.1.2
│   │ └── unmet dependency yallist@3.0.3
│   ├─┬ unmet optional dependency minizlib@1.2.1
│   │ └── unmet dependency minipass@2.3.5
│   ├── unmet dependency mkdirp@0.5.1
│   ├── unmet dependency safe-buffer@5.1.2
│   └── unmet dependency yallist@3.0.3
├─┬ glob-parent@3.1.0
│ ├─┬ is-glob@3.1.0
│ │ └── is-extglob@2.1.1 deduped
│ └── path-dirname@1.0.2
├── inherits@2.0.3
├─┬ is-binary-path@1.0.1
│ └── binary-extensions@1.13.1
├─┬ is-glob@4.0.1
│ └── is-extglob@2.1.1
├── normalize-path@3.0.0
├── path-is-absolute@1.0.1
├─┬ readdirp@2.2.1
│ ├── graceful-fs@4.1.15
│ ├── micromatch@3.1.10 deduped
│ └─┬ readable-stream@2.3.6
│  ├── core-util-is@1.0.2
│  ├── inherits@2.0.3 deduped
│  ├── isarray@1.0.0
│  ├── process-nextick-args@2.0.0
│  ├── safe-buffer@5.1.2
│  ├─┬ string_decoder@1.1.1
│  │ └── safe-buffer@5.1.2 deduped
│  └── util-deprecate@1.0.2
└── upath@1.1.2

npm err! missing: mkdirp@0.5.1, required by node-pre-gyp@0.10.3
npm err! missing: minimist@0.0.8, required by mkdirp@0.5.1
npm err! missing: minimatch@3.0.4, required by ignore-walk@3.0.1
npm err! missing: brace-expansion@1.1.11, required by minimatch@3.0.4
npm err! missing: balanced-match@1.0.0, required by brace-expansion@1.1.11
npm err! missing: concat-map@0.0.1, required by brace-expansion@1.1.11
npm err! missing: console-control-strings@1.1.0, required by npmlog@4.1.2
npm err! missing: inherits@2.0.3, required by readable-stream@2.3.6
npm err! missing: safe-buffer@5.1.2, required by readable-stream@2.3.6
npm err! missing: safe-buffer@5.1.2, required by string_decoder@1.1.1
npm err! missing: console-control-strings@1.1.0, required by gauge@2.7.4
npm err! missing: string-width@1.0.2, required by gauge@2.7.4
npm err! missing: strip-ansi@3.0.1, required by gauge@2.7.4
npm err! missing: code-point-at@1.1.0, required by string-width@1.0.2
npm err! missing: is-fullwidth-code-point@1.0.0, required by string-width@1.0.2
npm err! missing: strip-ansi@3.0.1, required by string-width@1.0.2
npm err! missing: number-is-nan@1.0.1, required by is-fullwidth-code-point@1.0.0
npm err! missing: ansi-regex@2.1.1, required by strip-ansi@3.0.1
npm err! missing: string-width@1.0.2, required by wide-align@1.1.3
npm err! missing: inherits@2.0.3, required by glob@7.1.3
npm err! missing: minimatch@3.0.4, required by glob@7.1.3
npm err! missing: once@1.4.0, required by glob@7.1.3
npm err! missing: once@1.4.0, required by inflight@1.0.6
npm err! missing: wrappy@1.0.2, required by inflight@1.0.6
npm err! missing: wrappy@1.0.2, required by once@1.4.0
npm err! missing: minipass@2.3.5, required by tar@4.4.8
npm err! missing: mkdirp@0.5.1, required by tar@4.4.8
npm err! missing: safe-buffer@5.1.2, required by tar@4.4.8
npm err! missing: yallist@3.0.3, required by tar@4.4.8
npm err! missing: minipass@2.3.5, required by fs-minipass@1.2.5
npm err! missing: safe-buffer@5.1.2, required by minipass@2.3.5
npm err! missing: yallist@3.0.3, required by minipass@2.3.5
npm err! missing: minipass@2.3.5, required by minizlib@1.2.1

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：

└─┬ chokidar@2.1.5
└── fsevents@1.2.7 

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。