The proposed workarounds above did work for me but there is now a much more elegant solution, tested for Angular9 and above.

No need to mess around manually with the JS heap allocation anymore (node --max_old_space_size=4096...), which most of us are not comfortable with.

The solution is just to add "sideEffects": false to your package.json file.

I found this awesome solution on the official Angular GitHub issues page here and it works smoothly for me.

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.

I have also met the same issue, by changing the angular/cli version to 8.3.19, the issue has been resolved.

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

Use

node --max_old_space_size=6144 ./node_modules/@angular/cli/bin/ng build

I ran into a similar issue a few days ago.

I was using Node v10 and could only avoid the exceptions during production build by changing to "target": "es5" in tsconfig.json. This removed differential loading, which was undesireable.

However, after updating to Node v14, I no longer get the exceptions and am able to use "target": "es2015" again.

In my case I upgraded the version of node.

I was running v10.* and I upgraded to v12.20.1 and build was completed.

I use Node Version Manager: nvm for switching versions of node.

For react-natives, you can find this helpful.

thank me later

npm  install --save-dev  escape-string-regexp

This only applicable for those who have migrated their app to angular 10 and increasing memory also not helping

check your "typescript" and "@types/node" in package.json check whether they are compatible or not in https://www.npmjs.com/package/@types/node

try to downgrade @angular-devkit/build-angular below 0.8XX.X