Angular 8 npm install fails - angular8

Question

I just recently upgraded to Angular 8 and my local build passing with aot. But in Jenkins build getting failed with below error. Can anyone help?
Here is the error
npm install
npm WARN deprecated core-js#2.6.11: core-js#<3 is no longer maintained and not recommended for usage due to the number of issues.
Please, upgrade your dependencies to the actual version of core-js#3.
npm WARN deprecated circular-json#0.5.9: CircularJSON is in maintenance only, flatted is its successor.
npm WARN deprecated uws#9.148.0: New code is available at github.com/uNetworking/uWebSockets.js
npm ERR! path git
npm ERR! code ENOENT
npm ERR! errno ENOENT
npm ERR! syscall spawn git
npm ERR! enoent Error while executing:
npm ERR! enoent undefined ls-remote -h -t ssh://git#github.com/pemrouz/buble.git
npm ERR! enoent
npm ERR! enoent
npm ERR! enoent spawn git ENOENT
npm ERR! enoent This is related to npm not being able to find a file.
npm ERR! enoent
npm ERR! A complete log of this run can be found in:
npm ERR! /root/.npm/_logs/2020-01-25T10_05_09_308Z-debug.log
here is my package json
"name": "olam-global-survey-app",
"version": "0.0.0",
"scripts": {
"ng": "ng",
"start": "ng serve",
"build": "ng build",
"test": "ng test",
"lint": "ng lint",
"e2e": "ng e2e"
},
"private": true,
"dependencies": {
"#angular/animations": "~8.2.14",
"#angular/common": "~8.2.14",
"#angular/compiler": "~8.2.14",
"#angular/core": "~8.2.14",
"#angular/forms": "~8.2.14",
"#angular/platform-browser": "~8.2.14",
"#angular/platform-browser-dynamic": "~8.2.14",
"#angular/router": "~8.2.14",
"popper": "^1.0.1",
"rxjs": "^6.2.1",
"rxjs-compat": "^6.2.1",
"tslib": "^1.9.0",
"zone.js": "~0.9.1"
},
"devDependencies": {
"#angular-devkit/build-angular": "~0.803.23",
"#angular/cli": "~8.3.23",
"#angular/compiler-cli": "~8.2.14",
"#angular/language-service": "~8.2.14",
"#types/node": "~8.9.4",
"#types/jasmine": "~2.8.8",
"#types/jasminewd2": "~2.0.3",
"codelyzer": "^5.0.1",
"jasmine-core": "~2.99.1",
"jasmine-spec-reporter": "~4.2.1",
"karma": "~3.1.1",
"karma-chrome-launcher": "~2.2.0",
"karma-coverage-istanbul-reporter": "~2.0.1",
"karma-jasmine": "~1.1.2",
"karma-jasmine-html-reporter": "^0.2.2",
"protractor": "~5.4.0",
"ts-node": "~7.0.0",
"tslint": "~5.11.0",
"typescript": "~3.5.3"
}
}

Answer 1

It's a npm cache problem.
just find npm-cache folder and delete it,
open terminal in administrator mode or use sudo if your OS supports linux
or
use npm clean-install

Answer 2

When you upgrade angular 8 its installs all default packages with Bootstrap 4. Bootstrap 4 installs popper.js package which helps for tooltip
Initial popper.js version will be ^1.0.1 and it is not supported with Angular 8 and Node 13. So we have to upgrade the package to version "popper.js": "^1.16.1"