Ionic pro error on building

I’m having this error while building the app on Ionic Pro. I’m very new to ionic , please help. Checkout the screenshot

You can see the codes in the screenshot here -

Running with gitlab-ci-multi-runner 9.1.0 (0118d89)
on ip-10-2-8-124 (c9648220)
Using Shell executor…
Running on ip-10-2-8-124…
Cloning repository…
Cloning into ‘/home/gitlab-runner/builds/c9648220/0/project-1’…
Checking out 78fcabac as master…
Skipping Git submodules setup
run "fetch-updates" Running Stage fetch-updates for Job: 5402682 Checking for build process updates... run “build-app”
Running Stage build-app for Job: 5402682
Parsing ionic.config.json for project settings
Project Settings:
Name: WooIonic
App ID: dc2ddcbe
Type: ionic-angular
Build script detected in package.json…
$ npm install --quiet --no-optional

node-sass@4.7.2 install /usr/src/app/node_modules/node-sass
node scripts/install.js

Downloading binary from
Download complete
Binary saved to /usr/src/app/node_modules/node-sass/vendor/linux-x64-57/binding.node
Caching binary to /home/gitlab-runner/.npm/node-sass/4.7.2/linux-x64-57_binding.node

uglifyjs-webpack-plugin@0.4.6 postinstall /usr/src/app/node_modules/uglifyjs-webpack-plugin
node lib/post_install.js

node-sass@4.7.2 postinstall /usr/src/app/node_modules/node-sass
node scripts/build.js

Binary found at /usr/src/app/node_modules/node-sass/vendor/linux-x64-57/binding.node
Testing binary
Binary is fine
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.1.3 (node_modules/fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.1.3: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“x64”})

added 962 packages in 23.633s
npm install --quiet --no-optional success npm run build
npm info it worked if it ends with ok
npm info using npm@5.3.0
npm info using node@v8.2.1
npm info lifecycle WooIonic@0.0.1~prebuild: WooIonic@0.0.1
npm info lifecycle WooIonic@0.0.1~build: WooIonic@0.0.1

WooIonic@0.0.1 build /usr/src/app
ionic-app-scripts build

[07:16:35] ionic-app-scripts 3.1.8
[07:16:35] build dev started …
[07:16:35] clean started …
[07:16:35] clean finished in 1 ms
[07:16:35] copy started …
[07:16:35] deeplinks started …
[07:16:35] deeplinks finished in 114 ms
[07:16:35] transpile started …
[07:16:38] transpile finished in 3.41 s
[07:16:38] preprocess started …
[07:16:38] preprocess finished in 1 ms
[07:16:38] webpack started …
[07:16:38] copy finished in 3.72 s
[07:16:48] webpack finished in 9.73 s
[07:16:48] sass started …
Without from option PostCSS could generate wrong source map and will not find Browserslist config. Set it to CSS file path or to undefined to prevent this warning.
[07:16:49] sass finished in 1.09 s
[07:16:49] postprocess started …
[07:16:49] ionic-app-script task: “build”
[07:16:49] Error: ENOENT: no such file or directory, open ‘/usr/src/app/www/index.html’
Error: ENOENT: no such file or directory, open ‘/usr/src/app/www/index.html’
npm info lifecycle WooIonic@0.0.1~build: Failed to exec build script
npm ERR! errno 1
npm ERR! WooIonic@0.0.1 build: ionic-app-scripts build
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the WooIonic@0.0.1 build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR! /home/gitlab-runner/.npm/_logs/2018-03-18T07_16_49_646Z-debug.log
npm run build failed
Running after script…
$ run “clean-up”
Running Stage clean-up for Job: 5402682
ERROR: Job failed: exit status 1