Call retries were exceeded exception while ng build

For me editing tsconfig.json resolved my problem.

There was a change in @angular-devkit/build-angular which updated the differential loading. To fix this in your Ionic project, change the target value from “es2015” to “es5” in your tsconfig.json

For more details :- https://forum.ionicframework.com/t/ionic-cordova-build-get-stuck-at-generating-es5-bundles-for-differential-loading/180202/4

Update 10.02.2019

This was a problem of the @angular/cli. Updating the version to >= 8.3.22 should fix the issue: see this comment in #16515

ORIGINAL

Basically the build process is running out of memory: see related angular-cli issues #15493, #16515

The recommended remedy is to:

• update node to the latest version e.g. 12.14.0
• increase the memory for the build process:
  • in your package.json change the "build" script to: node --max_old_space_size=4096 node_modules/@angular/cli/bin/ng build
  • in this case the memory is increased to 4GB
    depending on the size of your project you may need more

As a quick workaround it could also work to use older versions of angular/cli and build-angular:

"devDependencies": {
    "@angular-devkit/build-angular": "0.803.20",
    "@angular/cli": "8.3.20",

Another workaround is to disable differential-loading (i.e. skip generation of ES5 bundles), if you want this. Then the build-process will need less memory and may work.