npm ERR! missing script: build:universal - node.js

Question

I am trying to run my Angular application on the server side and I am facing these errors:
npm ERR! missing script: build:universal
npm ERR! A complete log of this run can be found in: npm ERR!
/home/training/.npm/_logs/2018-10-03T11_50_40_593Z-debug.log
I used the official Angular application for doing this
https://angular.io/guide/universal
The universal build is causing errors shown below:
0 info it worked if it ends with ok
1 verbose cli [ '/usr/bin/nodejs',
1 verbose cli '/usr/local/bin/npm',
1 verbose cli 'run',
1 verbose cli 'build:universal' ]
2 info using npm#6.2.0
3 info using node#v10.8.0
4 verbose stack Error: missing script: build:universal
4 verbose stack at run (/usr/local/lib/node_modules/npm/lib/run-script.js:155:19)
4 verbose stack at /usr/local/lib/node_modules/npm/lib/run-script.js:63:5
4 verbose stack at /usr/local/lib/node_modules/npm/node_modules/read-package-json/read-json.js:115:5
4 verbose stack at /usr/local/lib/node_modules/npm/node_modules/read-package-json/read-json.js:418:5
4 verbose stack at checkBinReferences_ (/usr/local/lib/node_modules/npm/node_modules/read-package-json/read-json.js:373:45)
4 verbose stack at final (/usr/local/lib/node_modules/npm/node_modules/read-package-json/read-json.js:416:3)
4 verbose stack at then (/usr/local/lib/node_modules/npm/node_modules/read-package-json/read-json.js:160:5)
4 verbose stack at /usr/local/lib/node_modules/npm/node_modules/read-package-json/read-json.js:280:12
4 verbose stack at /usr/local/lib/node_modules/npm/node_modules/graceful-fs/graceful-fs.js:78:16
4 verbose stack at FSReqWrap.readFileAfterClose [as oncomplete] (internal/fs/read_file_context.js:53:3)
5 verbose cwd /home/training/Desktop/vishnu/TemplateAppv6
6 verbose Linux 4.4.0-134-generic
7 verbose argv "/usr/bin/nodejs" "/usr/local/bin/npm" "run" "build:universal"
8 verbose node v10.8.0
9 verbose npm v6.2.0
10 error missing script: build:universal
11 verbose exit [ 1, true ]

Answer 1

As implied in my comment, you may have forgotten to add the build-script to your project:
From the universal docs
Build and run with universal: Now that you've created the TypeScript
and Webpack config files and configured the Angular CLI, you can build
and run the Universal application.
First add the build and serve commands to the scripts section of the
package.json:
"scripts": {
...
"build:ssr": "npm run build:client-and-server-bundles && npm run webpack:server",
"serve:ssr": "node dist/server",
"build:client-and-server-bundles": "ng build --prod && ng run angular.io-example:server",
"webpack:server": "webpack --config webpack.server.config.js --progress --colors"
...
}
So check you package.json and try the build again..