Angular 12 – Generating browser application bundles (phase: sealing) very slow

I try to do a lot of stuff to solve that issue, but hopefully I can reduce my changes to two important points:

1. update angular 12.0.0 to angular 12.0.2
2. set defaultConfiguration in angular.json to development ("defaultConfiguration": "development")

"defaultConfiguration": "production"

Build at: 2021-05-29T06:49:51.461Z - Hash: 9d68fbaa715d790c89ed - Time: 29446ms <- change one character in string
Build at: 2021-05-29T06:50:31.850Z - Hash: cc2399413ce6f0800553 - Time: 32195ms <- change one character in string

"defaultConfiguration": "development"

Build at: 2021-05-29T06:52:16.258Z - Hash: b9b4991fa89ef1e785fc - Time: 781ms <- change one character in string
Build at: 2021-05-29T06:52:27.484Z - Hash: 3838e3c45e33228591f9 - Time: 622ms <- change one character in string

final angular.json

• "sourceMap": true is important for me
• simply call ng serve, no additional parameters needed

{
  "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
  "version": 1,
  "newProjectRoot": "projects",
  "projects": {
    "dotbot": {
      "projectType": "application",
      "schematics": {
        "@schematics/angular:component": {
          "style": "scss"
        }
      },
      "root": "",
      "sourceRoot": "src",
      "prefix": "dotbot",
      "architect": {
        "build": {
          "builder": "@angular-devkit/build-angular:browser",
          "options": {
            "outputPath": "dist/dotbot",
            "index": "src/index.html",
            "main": "src/main.ts",
            "polyfills": "src/polyfills.ts",
            "tsConfig": "tsconfig.json",
            "inlineStyleLanguage": "scss",
            "assets": ["src/favicon.ico", "src/assets"],
            "styles": ["./node_modules/@angular/material/_theming.scss", "src/styles.scss"],
            "scripts": []
          },
          "configurations": {
            "production": {
              "budgets": [
                {
                  "type": "initial",
                  "maximumWarning": "500kb",
                  "maximumError": "1mb"
                },
                {
                  "type": "anyComponentStyle",
                  "maximumWarning": "2kb",
                  "maximumError": "4kb"
                }
              ],
              "fileReplacements": [
                {
                  "replace": "src/environments/environment.ts",
                  "with": "src/environments/environment.prod.ts"
                }
              ],
              "outputHashing": "all"
            },
            "development": {
              "buildOptimizer": false,
              "optimization": {
                "scripts": false,
                "styles": false,
                "fonts": false
              },
              "vendorChunk": true,
              "extractLicenses": false,
              "sourceMap": true,
              "namedChunks": true
            }
          },
          "defaultConfiguration": "development"
        },
        "serve": {
          "builder": "@angular-devkit/build-angular:dev-server",
          "options": {
            "browserTarget": "dotbot:build"
          },
          "configurations": {
            "production": {
              "browserTarget": "dotbot:build:production"
            }
          }
        },
        "extract-i18n": {
          "builder": "@angular-devkit/build-angular:extract-i18n",
          "options": {
            "browserTarget": "dotbot:build"
          }
        },
        "test": {
          "builder": "@angular-devkit/build-angular:karma",
          "options": {
            "main": "src/test.ts",
            "polyfills": "src/polyfills.ts",
            "tsConfig": "tsconfig.spec.json",
            "karmaConfig": "karma.conf.js",
            "inlineStyleLanguage": "scss",
            "assets": ["src/favicon.ico", "src/assets"],
            "styles": ["./node_modules/@angular/material/prebuilt-themes/indigo-pink.css", "src/styles.scss"],
            "scripts": []
          }
        },
        "lint": {
          "builder": "@angular-devkit/build-angular:tslint",
          "options": {
            "tsConfig": ["tsconfig.app.json", "tsconfig.spec.json", "e2e/tsconfig.json"],
            "exclude": ["**/node_modules/**"]
          }
        },
        "e2e": {
          "builder": "@angular-devkit/build-angular:protractor",
          "options": {
            "protractorConfig": "e2e/protractor.conf.js",
            "devServerTarget": "dotbot:serve"
          },
          "configurations": {
            "production": {
              "devServerTarget": "dotbot:serve:production"
            }
          }
        }
      }
    }
  },
  "defaultProject": "dotbot"
}