Angular 9 upgrade peer dependency issue

Question

When I try to upgrade angular using its documentation to version 9, I get following peer dependency error:

Package "@angular/compiler-cli" has a missing peer dependency of "tslib" @ "^1.10.0". Package "@angular/animations" has a missing peer dependency of "tslib" @ "^1.10.0". Package "@angular/common" has a missing peer dependency of "tslib" @ "^1.10.0". Package "@angular/compiler" has a missing peer dependency of "tslib" @ "^1.10.0". Package "codelyzer" has an incompatible peer dependency to "@angular/compiler" (requires ">=2.3.1 <8.0.0 || >7.0.0-beta <8.0.0" (extended), would install "9.1.13"). Package "@angular/core" has a missing peer dependency of "tslib" @ "^1.10.0". Package "codelyzer" has an incompatible peer dependency to "@angular/core" (requires ">=2.3.1 <8.0.0 || >7.0.0-beta <8.0.0" (extended), would install "9.1.13"). Package "@angular/forms" has a missing peer dependency of "tslib" @ "^1.10.0". Package "@angular/platform-browser" has a missing peer dependency of "tslib" @ "^1.10.0". Package "@angular/http" has an incompatible peer dependency to "@angular/platform-browser" (requires "7.2.16" (extended), would install "9.1.13"). Package "@angular/platform-browser-dynamic" has a missing peer dependency of "tslib" @ "^1.10.0". Package "@angular/router" has a missing peer dependency of "tslib" @ "^1.10.0".

Here are the dependencies:

"dependencies": {
    "@angular/animations": "^8.2.14",
    "@angular/cdk": "^7.3.7",
    "@angular/common": "^8.2.14",
    "@angular/compiler": "^8.2.14",
    "@angular/core": "^8.2.14",
    "@angular/forms": "^8.2.14",
    "@angular/http": "^7.2.16",
    "@angular/material": "^7.3.7",
    "@angular/platform-browser": "^8.2.14",
    "@angular/platform-browser-dynamic": "^8.2.14",
    "@angular/router": "^8.2.14",
    "@types/underscore": "^1.8.8",
    "ang-jsoneditor": "^1.6.2",
    "core-js": "^2.4.1",
    "cors": "^2.8.4",
    "hammerjs": "^2.0.8",
    "jsoneditor": "^5.24.7",
    "jsoneditor2": "^1.0.0",
    "lodash": "^4.17.20",
    "moment": "^2.24.0",
    "ng-multiselect-dropdown": "0.2.4",
    "ngx-ace-wrapper": "^7.3.0",
    "ngx-ui-loader": "^7.2.2",
    "rxjs": "^6.6.3",
    "rxjs-compat": "^6.6.3",
    "underscore": "^1.9.1",
    "zone.js": "^0.9.1"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "^0.803.29",
    "@angular/cli": "^8.3.29",
    "@angular/compiler-cli": "^8.2.14",
    "@angular/language-service": "^8.2.14",
    "@compodoc/compodoc": "^1.1.11",
    "@types/jasmine": "~2.8.3",
    "@types/jasminewd2": "~2.0.2",
    "@types/node": "~6.0.60",
    "codelyzer": "^4.5.0",
    "express": "^4.16.3",
    "jasmine-core": "~2.8.0",
    "jasmine-spec-reporter": "~4.2.1",
    "karma": "~2.0.0",
    "karma-chrome-launcher": "~2.2.0",
    "karma-coverage-istanbul-reporter": "^1.2.1",
    "karma-jasmine": "~1.1.0",
    "karma-jasmine-html-reporter": "^0.2.2",
    "mini-css-extract-plugin": "^0.8.0",
    "protractor": "^5.3.2",
    "ts-node": "~4.1.0",
    "tslint": "~5.9.1",
    "typescript": "^3.5.3"
  }

Any suggestion?

Answer 1

The --force flag is the only thing that worked for me:

ng update --force @angular/core@9 @angular/cli@9

Answer 2

For me nothing worked. So I manually changed the version of tslib to the one it's complaining about... and it worked!