title: npm run build on multiple environments without mention specified environment
body: <p>I am using angular project with multiple environment. Whenever doing build taking so long time for single environment. How can i reduce it. I have added my project configuration here.</p>
  
  <p>package.json:</p>
  
  <pre><code>{
    "name": "test",
    "version": "0.0.0",
    "license": "MIT",
    "scripts": {
      "ng": "ng",
      "start": "node --max_old_space_size=10240 ./node_modules/@angular/cli/bin/ng serve --aot",
      "build": "rimraf dist &amp;&amp; node --max_old_space_size=10240 ./node_modules/@angular/cli/bin/ng build",
      "test": "ng test",
      "lint": "ng lint",
      "e2e": "ng e2e",
      "build:universal": "npm run build:client-and-server-bundles &amp;&amp; npm run webpack:server",
      "serve:universal": "node dist/server.js",
      "build:client-and-server-bundles": "ng build --prod &amp;&amp; ng build --prod --app 1 --output-hashing=false",
      "webpack:server": "webpack --config webpack.server.config.js --progress --colors",
      "postbuild": "node zipbuild"
    },
    "private": true,
    "dependencies": {
      "@angular-devkit/core": "7.3.3",
      "@angular/animations": "7.2.6",
      "@angular/cdk": "^7.3.3",
      "@angular/cli": "7.3.3",
      "@angular/common": "7.2.6",
      "@angular/compiler": "7.2.6",
      "@angular/core": "7.2.6",
      "@angular/flex-layout": "7.0.0-beta.23",
      "@angular/forms": "7.2.6",
      "@angular/http": "7.2.6",
      "@angular/material": "^7.3.3",
      "@angular/platform-browser": "7.2.6",
      "@angular/platform-browser-dynamic": "7.2.6",
      "@angular/platform-server": "7.2.6",
      "@angular/router": "7.2.6",
    },
    "devDependencies": {
      "@angular-devkit/build-angular": "~0.13.3",
      "@angular/compiler-cli": "7.2.6",
      "@angular/language-service": "7.2.6",
      "@types/jasmine": "~3.3.9",
      "@types/jasminewd2": "~2.0.6",
      "@types/node": "^11.9.5",
      "codelyzer": "^4.5.0",
      "css-loader": "2.1.0",
      "jasmine-core": "^3.3.0",
      "jasmine-spec-reporter": "^4.2.1",
      "karma": "~4.0.0",
      "karma-chrome-launcher": "~2.2.0",
      "karma-coverage-istanbul-reporter": "^2.0.5",
      "karma-jasmine": "^2.0.1",
      "karma-jasmine-html-reporter": "^1.4.0",
      "protractor": "^5.4.2",
      "ts-node": "^8.0.2",
      "tslint": "^5.13.0",
      "typescript": "3.2.4"
    }
  }
  </code></pre>
  
  <p>angular.json:</p>
  
  <pre><code>    {
        "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
        "version": 1,
        "newProjectRoot": "projects",
        "projects": {
          "test": {
            "root": "",
            "sourceRoot": "src",
            "projectType": "application",
            "architect": {
              "build": {
                "builder": "@angular-devkit/build-angular:browser",
                "options": {
                  "outputPath": "dist",
                  "index": "src/index.html",
                  "main": "src/main.ts",
                  "tsConfig": "src/tsconfig.app.json",
                  "polyfills": "src/polyfills.ts",
                  "assets": [
                    "src/assets",
                    "src/favicon.ico",
                    "src/web.config"
                  ],
                  "styles": [
                    "src/styles.scss"
                  ],
                  "scripts": [
                    "src/assets/SigWebTablet.js"
                  ]
                },
                "configurations": {
                  "demo": {
                    "optimization": true,
                    "outputHashing": "all",
                    "sourceMap": false,
                    "extractCss": true,
                    "namedChunks": false,
                    "aot": true,
                    "extractLicenses": true,
                    "vendorChunk": false,
                    "buildOptimizer": true,
                    "outputPath": "dist/demo",
                    "fileReplacements": [
                      {
                        "replace": "src/environments/environment.ts",
                        "with": "src/environments/environment.demo.ts"
                      }
                    ]
                  },
  "demo1": {
                    "optimization": true,
                    "outputHashing": "all",
                    "sourceMap": false,
                    "extractCss": true,
                    "namedChunks": false,
                    "aot": true,
                    "extractLicenses": true,
                    "vendorChunk": false,
                    "buildOptimizer": true,
                    "outputPath": "dist/demo",
                    "fileReplacements": [
                      {
                        "replace": "src/environments/environment.ts",
                        "with": "src/environments/environment.demo.ts"
                      }
                    ]
                  }
                }
              },
              "serve": {
                "builder": "@angular-devkit/build-angular:dev-server",
                "options": {
                  "browserTarget": "test:build"
                },
                "configurations": {
                  "production": {
                    "browserTarget": "test:build:production"
                  },
                  "sacramento": {
                    "browserTarget": "test:build:sacramento"
                  },
                  "denver": {
                    "browserTarget": "test:build:denver"
                  },
                  "orange": {
                    "browserTarget": "test:build:orange"
                  },
                  "slo": {
                    "browserTarget": "test:build:slo"
                  }
                }
              },
              "extract-i18n": {
                "builder": "@angular-devkit/build-angular:extract-i18n",
                "options": {
                  "browserTarget": "atims-prebook:build"
                }
              },
              "test": {
                "builder": "@angular-devkit/build-angular:karma",
                "options": {
                  "main": "src/test.ts",
                  "karmaConfig": "./karma.conf.js",
                  "polyfills": "src/polyfills.ts",
                  "tsConfig": "src/tsconfig.spec.json",
                  "scripts": [],
                  "styles": [
                    "src/styles.scss"
                  ],
                  "assets": [
                    "src/assets",
                    "src/favicon.ico"
                  ]
                }
              },
              "lint": {
                "builder": "@angular-devkit/build-angular:tslint",
                "options": {
                  "tsConfig": [
                    "src/tsconfig.app.json",
                    "src/tsconfig.spec.json"
                  ],
                  "exclude": [
                    "**/node_modules/**"
                  ]
                }
              },
              "server": {
                "builder": "@angular-devkit/build-angular:server",
                "options": {
                  "outputPath": "dist/server",
                  "main": "main.server.ts",
                  "tsConfig": "tsconfig.server.json"
                }
              }
            }
          },
          "test-e2e": {
            "root": "",
            "sourceRoot": "e2e",
            "projectType": "application",
            "architect": {
              "e2e": {
                "builder": "@angular-devkit/build-angular:protractor",
                "options": {
                  "protractorConfig": "./protractor.conf.js",
                  "devServerTarget": "test:serve"
                }
              },
              "lint": {
                "builder": "@angular-devkit/build-angular:tslint",
                "options": {
                  "tsConfig": [
                    "e2e/tsconfig.e2e.json"
                  ],
                  "exclude": [
                    "**/node_modules/**"
                  ]
                }
              }
            }
          }
        },
        "defaultProject": "test",
        "schematics": {
          "@schematics/angular:class": {
            "spec": false
          },
          "@schematics/angular:component": {
            "spec": false,
            "prefix": "pbpc",
            "styleext": "scss"
          },
          "@schematics/angular:directive": {
            "spec": false,
            "prefix": "pbpc"
          },
          "@schematics/angular:guard": {
            "spec": false
          },
          "@schematics/angular:module": {
            "spec": false
          },
          "@schematics/angular:pipe": {
            "spec": false
          },
          "@schematics/angular:service": {
            "spec": false
          }
        }
      }
  </code></pre>
  
  <p>I am using command to build is "<strong>npm run build -- --c demo</strong>" &amp; "<strong>npm run build -- --c demo1</strong>" to build in separate command prompt. For each single build is approximately taking 20 to 30min. Do we have any option to build in single query?</p>