Ionic cordova build Get Stuck at "Generating ES5 bundles for differential loading..."

When I was building my ionic app via “ionic cordova run android --device --verbose”, it got stuck at …

> ng.cmd run app:ionic-cordova-build --platform=android
  ng:analytics getGlobalAnalytics +0ms
  ng:analytics Client Analytics config found: false +38ms
  ng:analytics Analytics disabled. Ignoring all analytics. +0ms
  ng:analytics getSharedAnalytics +1ms
Generating ES5 bundles for differential loading...

I had been loading for over 10 minutes. I don’t know how to handle!

Here is the information of the modules:

npm: 6.9.0
ionic: 5.4.13
cordova: 9.0.0 (cordova-lib@9.0.1)

Thank you.


One thing you can try is to make it not do that.

Change your browserslist to read:

last 2 Chrome versions
last 2 Safari versions

(for example), and it won’t bother building ES5 bundles.


My existing browserlist:

# This file is used by the build system to adjust CSS and JS output to support the specified browsers below.
# For additional information regarding the format and rule options, please see:

# You can see what browsers were selected by your queries by running:
#   npx browserslist

> 0.5%
last 2 versions
Firefox ESR
not dead
not IE 9-11 # For IE 9-11 support, remove 'not'.

How should I place your things? Thanks.

Same issue here. Running the cordova build command with --verbose, I get this error message:

[error] Error: Call retries were exceeded
    at ChildProcessWorker.initialize (/Users/me/Documents/apps/myapp/node_modules/jest-worker/build/workers/ChildProcessWorker.js:193:21)
    at ChildProcessWorker.onExit (/Users/me/Documents/apps/myapp/node_modules/jest-worker/build/workers/ChildProcessWorker.js:263:12)
    at ChildProcess.emit (events.js:198:13)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:248:12)

It seems to be connected with this issue:

But I still can’t manage to get it solved.

Edit: Error occurs on one of my projects only. For all others I can build without any problems. Could there be a performance issue with cordova/Ionic? My machine (MBP, 2,7 GHz i7, 16 GB RAM) should be able to build my projects I guess…

EDIT2 / Temporary solution:
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:

  "compileOnSave": false,
  "compilerOptions": {
    "baseUrl": "./",
    "outDir": "./dist/out-tsc",
    "sourceMap": true,
    "declaration": false,
    "module": "esnext",
    "moduleResolution": "node",
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "importHelpers": true,
    "target": "es5",
    "typeRoots": [
    "lib": [
  "angularCompilerOptions": {
    "fullTemplateTypeCheck": true,
    "strictInjectionParameters": true

Let’s hope there’s a real fix for that soon but in the meantime we at least can build our projects.


This actually assisted me very much. I was able to build my project and run it on a real device. Thank you!

Replace all lines that don’t start with a # with them.

1 Like

Bingo result, thanks

really thank you
it is useful for me

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Thanks a lot, this help me

Thank you! It works for me

Worked for me. Thank you!

Worked for me too :+1:

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thanks that sorted the issue for me to!

nice, helped me, now lets see if my google maps work haha thanks!