Saraiki (skr) missing from IntlCalendar::getAvailableLocales()

[jeherve]

Description

The following code:

<?php
if ( ! in_array( 'skr', IntlCalendar::getAvailableLocales(), true ) ) {
    echo 'locale is not available';
}

Resulted in this output:

locale is not available

I expected the locale to be available, since skr is a valid ISO 639-3 language code for the Saraiki language, spoken by 20+ million people. Should it be added to the list of supported languages?

This issue may not be new, but after recent changes to NumberFormatter in PHP 8.4, it will now return a ValueError if the locale is invalid.

Code like below can consequently generate fatal errors now:

<?php
$formatter = new NumberFormatter( 'skr', 14 );
$formatter->setAttribute( 6, 1 );

echo $formatter->format( '123456' );

Resulted in this output in PHP 8.4:

PHP Fatal error:  Uncaught ValueError: NumberFormatter::__construct(): Argument #1 ($locale) "skr" is invalid in /test.php:2
Stack trace:
#0 test.php(2): NumberFormatter->__construct('skr', 14)
#1 {main}
  thrown in /test.php on line 2

While in PHP 8.3:

123.5K

PHP Version

PHP 8.4.6 (cli) (built: Apr  8 2025 19:55:31) (NTS)
Copyright (c) The PHP Group
Built by Homebrew
Zend Engine v4.4.6, Copyright (c) Zend Technologies
    with Zend OPcache v8.4.6, Copyright (c), by Zend Technologies

Operating System

No response

[MorganLOCode]

What version of the ICU tables do you have (what is the value of INTL_ICU_DATA_VERSION?). Saraiki was added in ICU version 76. I'm guessing you have 75; icu is one of those libraries where you need to recompile the application that uses it whenever it changes version.

[jeherve]

Thank you for the quick reply! I tried in 2 different systems, but the fatal happened regardless of the INTL_ICU_DATA_VERSION version.

<?php

echo 'Current PHP version: ' . phpversion();

echo "\n";

echo 'ICU tables: ' . INTL_ICU_DATA_VERSION;

echo "\n";

$formatter = new NumberFormatter( 'skr', 14 );
$formatter->setAttribute( 6, 1 );

echo $formatter->format( '123456' );

In the first environment:

Current PHP version: 8.4.6
ICU tables: 77.1
PHP Fatal error:  Uncaught ValueError: NumberFormatter::__construct(): Argument #1 ($locale) "skr" is invalid in /test.php:11
Stack trace:
#0 /test.php(11): NumberFormatter->__construct('skr', 14)
#1 {main}
  thrown in /test.php on line 11

In the second:

Current PHP version: 8.4.6
ICU tables: 72.1
PHP Fatal error:  Uncaught ValueError: NumberFormatter::__construct(): Argument #1 ($locale) "skr" is invalid in /test.php:11
Stack trace:
#0 /test.php(11): NumberFormatter->__construct('skr', 14)
#1 {main}
  thrown in /test.php on line 11

[MorganLOCode]

Well, I'm no expert on the Intl extension, but the first of the two environments is concerning since version 77.1 is recent enough (for the other one it could just be the old ICU version).

I thought maybe it was something stupid like not accepting three-letter locales, but Rajasthani ("raj") is recognised. So I'm not sure about this.

[nielsdos]

If you take a look at https://www.unicode.org/cldr/charts/47/supplemental/locale_coverage.html, you can see that "skr" is not included by default in ICU. You need to install the extra data with your package manager or manually (install icu-data-full on Alpine for example).
The reason this "worked" in 8.3 is because it's using the fallback locale without reporting an exception, i.e. it didn't actually work and you're relying on a bogus result.

[jeherve]

Thank you for the extra context!