title: Can't run ng serve because of error "Cannot find module '@angular/compiler-cli'"
body: <p>I have an Angular project, I can't run <code>ng serve</code> because it fails with the error:</p>
  
  <pre><code>dev@716a5115c45c:~/project$ npx ng serve
  Cannot find module '@angular/compiler-cli'
  Error: Cannot find module '@angular/compiler-cli'
      at Function.Module._resolveFilename (module.js:548:15)
      at Function.Module._load (module.js:475:25)
      at Module.require (module.js:597:17)
      at require (internal/module.js:11:18)
      at Object.&lt;anonymous&gt; (/home/dev/volume/cache/front-node-modules/@angular-devkit/build-angular/node_modules/@ngtools/webpack/src/angular_compiler_plugin.js:12:24)
      at Module._compile (module.js:653:30)
      at Object.Module._extensions..js (module.js:664:10)
      at Module.load (module.js:566:32)
      at tryModuleLoad (module.js:506:12)
      at Function.Module._load (module.js:498:3)
      at Module.require (module.js:597:17)
      at require (internal/module.js:11:18)
      at Object.&lt;anonymous&gt; (/home/dev/volume/cache/front-node-modules/@angular-devkit/build-angular/node_modules/@ngtools/webpack/src/index.js:13:10)
      at Module._compile (module.js:653:30)
      at Object.Module._extensions..js (module.js:664:10)
      at Module.load (module.js:566:32)
  </code></pre>
  
  <p>Here is my package.json:</p>
  
  <pre><code>{
    "name": "ruskline-front",
    "version": "0.0.0",
    "scripts": {
      "ng": "ng",
      "build-prod": "ng build --prod",
      "test": "ng test",
      "lint": "ng lint",
      "e2e": "ng e2e",
      "tsc": "tsc"
    },
    "private": true,
    "dependencies": {
      "@angular/animations": "^7.0.4",
      "@angular/cdk": "^7.1.0",
      "@angular/common": "~7.2.0",
      "@angular/compiler": "~7.2.0",
      "@angular/core": "~7.2.0",
      "@angular/flex-layout": "^7.0.0-beta.19",
      "@angular/forms": "~7.2.0",
      "@angular/http": "~7.2.0",
      "@angular/material": "^7.1.0",
      "@angular/platform-browser": "~7.2.0",
      "@angular/platform-browser-dynamic": "~7.2.0",
      "@angular/router": "~7.2.0",
      "core-js": "^2.5.4",
      "ng2-ckeditor": "1.2.2",
      "rxjs": "~6.3.3",
      "zone.js": "~0.8.26"
    },
    "devDependencies": {
      "@angular-devkit/build-angular": "~0.12.1",
      "@angular-devkit/build-ng-packagr": "~0.12.1",
      "@angular/cli": "~7.2.1",
      "@angular/compiler-cli": "~7.2.0",
      "@angular/language-service": "~7.2.0",
      "@types/jasmine": "~3.3.5",
      "@types/jasminewd2": "~2.0.3",
      "@types/node": "~10.12.18",
      "codelyzer": "~4.5.0",
      "css-loader": "^2.1.0",
      "jasmine-core": "~3.3.0",
      "jasmine-spec-reporter": "~4.2.1",
      "karma": "~3.1.4",
      "karma-chrome-launcher": "~2.2.0",
      "karma-coverage-istanbul-reporter": "~2.0.1",
      "karma-jasmine": "~2.0.1",
      "karma-jasmine-html-reporter": "^1.4.0",
      "ng-packagr": "^4.2.0",
      "protractor": "~5.4.0",
      "ts-node": "~7.0.0",
      "tsickle": "&gt;=0.29.0",
      "tslib": "^1.9.0",
      "tslint": "~5.12.1",
      "typescript": "~3.2.2",
      "webpack": "^4.28.4"
    }
  }
  </code></pre>
  
  <p><code>compiler-cli</code> is listed in there</p>
  
  <p>When I run <code>npm i</code> I get a lot of <code>WARN</code> messages, maybe I missed something?</p>
  
  <pre><code>dev@716a5115c45c:~/project$ npm i
  npm WARN @ngtools/webpack@7.2.1 requires a peer of @angular/compiler-cli@&gt;=5.0.0 &lt;8.0.0 || ^7.0.0-beta.0 but none is installed. You must install peer dependencies yourself.
  npm WARN tsutils@2.29.0 requires a peer of typescript@&gt;=2.1.0 || &gt;=2.1.0-dev || &gt;=2.2.0-dev || &gt;=2.3.0-dev || &gt;=2.4.0-dev || &gt;=2.5.0-dev || &gt;=2.6.0-dev || &gt;=2.7.0-dev || &gt;=2.8.0-dev || &gt;=2.9.0-dev || &gt;= 3.0.0-dev || &gt;= 3.1.0-dev but none is installed. You must install peer dependencies yourself.
  npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.4 (node_modules/webpack/node_modules/fsevents):
  npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.4: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
  npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.4 (node_modules/ng-packagr/node_modules/fsevents):
  npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.4: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
  npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.4 (node_modules/karma/node_modules/fsevents):
  npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.4: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
  npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.4 (node_modules/@angular/compiler-cli/node_modules/fsevents):
  npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.4: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
  npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.4 (node_modules/@angular/cli/node_modules/fsevents):
  npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.4: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
  npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.4 (node_modules/@angular-devkit/core/node_modules/fsevents):
  npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.4: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
  npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.4 (node_modules/@angular-devkit/build-ng-packagr/node_modules/fsevents):
  npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.4: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
  npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.4 (node_modules/@angular-devkit/build-angular/node_modules/fsevents):
  npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.4: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
  
  audited 54077 packages in 14.168s
  found 0 vulnerabilities
  </code></pre>
  
  <p>UPDATE:
  After @Melchia advices i have this error:</p>
  
  <pre><code>dev@e1f2820d1be5:~/project$ make start
  ./node_modules/.bin/ng serve --host 0.0.0.0
  module.js:550
      throw err;
      ^
  
  Error: Cannot find module 'symbol-observable'
      at Function.Module._resolveFilename (module.js:548:15)
      at Function.Module._load (module.js:475:25)
      at Module.require (module.js:597:17)
      at require (internal/module.js:11:18)
      at Object.&lt;anonymous&gt; (/home/dev/volume/cache/front-node-modules/@angular/cli/lib/init.js:10:1)
      at Module._compile (module.js:653:30)
      at Object.Module._extensions..js (module.js:664:10)
      at Module.load (module.js:566:32)
      at tryModuleLoad (module.js:506:12)
      at Function.Module._load (module.js:498:3)
  Makefile:5: recipe for target 'start' failed
  make: *** [start] Error 1
  </code></pre>