Locale data for 'en-US' cannot be found.

📚 Docs or angular.io bug report

Description

Issue first reported in 35776, referring to a stack overflow issue. The developer is getting this error message:

Locale data for 'en-US' cannot be found. No locale data will be included for this locale when running ng build --configuration=prod --localize

🔬 Minimal Reproduction

See the stack overflow issue.

What’s the affected URL?**

https://angular.io/guide/i18n#internationalization-i18n

Reproduction Steps**

See the stack overflow issue.

Expected vs Actual Behavior**

“The documentation clearly states en-US is imported by default. To make things worse, when i change sourceLocale to any other language (say ‘de’), warning message goes away. Manually registering en-US locale data doesn’t help either.”

📷Screenshot

🔥 Exception or Error

`Locale data for 'en-US' cannot be found.  No locale data will be included for this locale.`

🌍 Your Environment

Browser info

Anything else relevant?

[xiaoxiangmoe]

It seems that this problem has been fixed in ng 10, I am trying to migrate old projects to ng 10.

[Spawnrad]

Hi,

I have migrate from angular 8 to 9 and i have the same issue. My version : 9.1.11

The error message : Locale data for ‘fr-FR’ cannot be found. Using locale data for ‘fr’.

In my app.module i have : registerLocaleData(localeFr, 'fr-FR');

In my package.json :

      "i18n": {
        "sourceLocale": "fr-FR"
      },
....

"localize": ["fr-FR"],

When i change to “localize”: [“fr”] i have the error message : Requested locale ‘fr’ is not defined for the project.

If i use :

      "i18n": {
        "sourceLocale": "fr"
      },
`"localize": ["fr"],`

All work fine

Maybe need to change the documentation at the line :
https://angular.io/guide/i18n

"i18n": {
      "sourceLocale": "en-US"

Thanks