[ Intl ] An unexpected error occurred while trying to use PHP Intl Collator class

[mho22]

The following blueprint is outputting errors related to the Collator class, enabled by the static Intl extension.

{
  "login": true,
  "landingPage": "/wp-admin/",
  "features": {
    "intl": true
  },
  "steps": [
    {
      "step": "installPlugin",
      "pluginData": {
        "resource": "url",
        "url": "https://github-proxy.com/proxy/?repo=woocommerce/woocommerce&release=latest&asset=woocommerce.zip"
      },
      "options": {
        "activate": true,
        "targetFolderName": "wc"
      }
    },
    {
      "step": "installPlugin",
      "pluginData": {
        "resource": "url",
        "url": "https://github-proxy.com/proxy/?repo=woocommerce/wc-smooth-generator&release=latest&asset=wc-smooth-generator.zip"
      },
      "options": {
        "activate": true,
        "targetFolderName": "wc-smooth-generator"
      }
    }
  ]
}

[06-Aug-2025 09:08:37 UTC] An unexpected error occurred while trying to use PHP Intl Collator class, it may be caused by an incorrect installation of PHP Intl and ICU, and could be fixed by reinstallaing PHP Intl, see more details about PHP Intl installation: https://www.php.net/manual/en/intl.installation.php. Error message: Constructor failed
[06-Aug-2025 09:08:44 UTC] An unexpected error occurred while trying to use PHP Intl Collator class, it may be caused by an incorrect installation of PHP Intl and ICU, and could be fixed by reinstallaing PHP Intl, see more details about PHP Intl installation: https://www.php.net/manual/en/intl.installation.php. Error message: Constructor failed

The errors are printed from this WooCommerce file function :

function wc_asort_by_locale( &$data, $locale = '' ) {
	// Use Collator if PHP Internationalization Functions (php-intl) is available.
	if ( class_exists( 'Collator' ) ) {
		try {
			$locale   = $locale ? $locale : get_locale();
			$collator = new Collator( $locale );
			$collator->asort( $data, Collator::SORT_STRING );
			return $data;
		} catch ( IntlException $e ) {
			/*
			 * Just skip if some error got caused.
			 * It may be caused in installations that doesn't include ICU TZData.
			 */
			if ( Constants::is_true( 'WP_DEBUG' ) ) {
				error_log( // phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log
					sprintf(
						'An unexpected error occurred while trying to use PHP Intl Collator class, it may be caused by an incorrect installation of PHP Intl and ICU, and could be fixed by reinstallaing PHP Intl, see more details about PHP Intl installation: %1$s. Error message: %2$s',
						'https://www.php.net/manual/en/intl.installation.php',
						$e->getMessage()
					)
				);
			}
		}
	}

Constructor failed is a concise error returned by PHP from this file :

ext/intl/collator/collator_create.c

/* {{{ Collator object constructor. */
PHP_METHOD( Collator, __construct )
{
	zend_error_handling error_handling;
	bool error_handling_replaced = 0;

	return_value = ZEND_THIS;
	if (collator_ctor(INTERNAL_FUNCTION_PARAM_PASSTHRU, &error_handling, &error_handling_replaced) == FAILURE) {
		if (!EG(exception)) {
			zend_throw_exception(IntlException_ce_ptr, "Constructor failed", 0);
		}
	}
	if (error_handling_replaced) {
		zend_restore_error_handling(&error_handling);
	}
}
/* }}} */

When running the code returning an error in a blueprint :

{
  "features": {
    "intl": true
  },
  "landingPage": "/test.php",
  "steps": [
    {
      "step": "writeFile",
      "path": "/wordpress/test.php",
      "data": "<?php require_once '/wordpress/wp-load.php'; $data = [ 'banana', 'apple' ]; $locale = get_locale(); $collator = new Collator( $locale ); $collator->asort( $data, Collator::SORT_STRING ); echo '<div style=\"background-color: blue; color: white;\">'; print_r( $data ); echo '</div>'; ?>"
    }
  ]
}

It returns the correct sorted data : Array ( [1] => apple [0] => banana )

[mho22]

I suspect the first PHP runtime to have access to the ICU data, but the subsequent ones do not.

[bacoords]

Just adding that I get this error frequently testing WooCommerce on Playground.

[mho22]

@bacoords I'm on it. I'll keep you posted.

[mho22]

I tried to reproduce the error with multiple PHP runtimes using @php-wasm/web and the PHPProcessManager but everything is working as expected :

I'll leave the test files here for the record :

index.html

<!DOCTYPE html>

<html>
    <head>

        <script type="module" src="web.js"></script>

    </head>

    <body>

        <div id="app">Hello Intl world</div>

    </body>

</html>

web.js

import { PHP, PHPProcessManager } from '@php-wasm/universal';
import { loadWebRuntime, generateCertificate } from '@php-wasm/web';


const CAroot = await generateCertificate( {
    subject : {
        commonName: 'Foo',
        organizationName: 'Bar',
        countryName: 'Baz',
    },
    basicConstraints: {
        ca : true,
    },
});

let wasm = '';

const manager = new PHPProcessManager( {
	phpFactory : async () =>
		new PHP( await loadWebRuntime( '8.3', {

			tcpOverFetch : { CAroot },

			emscriptenOptions : { instantiateWasm( imports, receiveInstance ) { fetch( wasm, { credentials : 'same-origin' } ).then( async response => WebAssembly.instantiate( await response.arrayBuffer(), imports ).then( wasm => receiveInstance( wasm.instance, wasm.module ) ) ) } },

			onPhpLoaderModuleLoaded : phpLoaderModule => {

				wasm = phpLoaderModule.dependencyFilename;
			},

			withICU : true

		} ) ),
	maxPhpInstances : 3,
});


const script = `<?php

$data = [ 'banana', 'apple' ];

$collator = new Collator( 'en_US' );

$collator->asort( $data, Collator::SORT_STRING );

print_r( $data );`;


const primaryPhp = await manager.getPrimaryPhp();

const primaryResult = await primaryPhp.runStream( { code : script } );

console.log( await primaryResult.stdoutText );

console.log( primaryPhp.listFiles( 'internal/shared' ) );

const { php } = await manager.acquirePHPInstance( { considerPrimary : false } );

const secondResult = await php.runStream( { code: script } );

console.log( await secondResult.stdoutText );

console.log( php.listFiles( 'internal/shared' ) );

vite.config.js

import { defineConfig } from 'vite';

export default defineConfig( {
	optimizeDeps : { exclude : [ '@php-wasm/web' ] },
	build : { rollupOptions : { external : [ 'worker_threads' ] } },
	assetsInclude : [ "**/*.wasm", "**/*.dat" ]
} );

package.json

{
    "type" : "module",
    "scripts" : {
        "dev" : "vite",
        "build" : "vite build",
        "preview" : "vite preview"
    },
    "dependencies" : {
        "@php-wasm/universal" : "http://127.0.0.1:9724/a80ce9fb8bf792749bcb7033/v2.0.9/@php-wasm-universal-2.0.9.tar.gz",
        "@php-wasm/web" : "http://127.0.0.1:9724/a80ce9fb8bf792749bcb7033/v2.0.9/@php-wasm-web-2.0.9.tar.gz",
        "vite" : "^7.1.1"
    }
}

Results :

Array
(
    [1] => apple
    [0] => banana
)

['preload', 'bin', 'icudt74l.dat', 'opcache', 'php.ini', 'auto_prepend_file.php']
iArray
(
    [1] => apple
    [0] => banana
)

['preload', 'bin', 'icudt74l.dat', 'opcache', 'php.ini', 'auto_prepend_file.php']

I should investigate elsewhere. What about the error that is always preceding the Intl Collator error message :

[11-Aug-2025 14:07:42 UTC] PHP Notice:  Function _load_textdomain_just_in_time was called <strong>incorrectly</strong>. Translation loading for the <code>woocommerce</code> domain was triggered too early. This is usually an indicator for some code in the plugin or theme running too early. Translations should be loaded at the <code>init</code> action or later. Please see <a href="https://developer.wordpress.org/advanced-administration/debug/debug-wordpress/">Debugging in WordPress</a> for more information. (This message was added in version 6.7.0.) in /wordpress/wp-includes/functions.php on line 135
[11-Aug-2025 14:07:42 UTC] An unexpected error occurred while trying to use PHP Intl Collator class, it may be caused by an incorrect installation of PHP Intl and ICU, and could be fixed by reinstallaing PHP Intl, see more details about PHP Intl installation: https://www.php.net/manual/en/intl.installation.php. Error message: Constructor failed

It seems to indicate the _load_textdomain_just_in_time function is called too early.

But this error should be corrected in this pull request.

I should verify the version of woocommerce.

Sometimes, the blueprint runs without crashing or logging errors related to Intl.

[mho22]

@bacoords Writing a php file in /wordpress/wp-content/mu-plugins should do the trick for now :

{
  "login": true,
  "landingPage": "/wp-admin/",
  "features": {
    "intl": true
  },
  "steps": [
+    {
+     "step": "writeFile",
+      "path": "/wordpress/wp-content/mu-plugins/disable-wc-country-sort.php",
+      "data": "<?php /* Plugin Name: Disable WC Country Sort */ add_filter('woocommerce_sort_countries','__return_false',0);"
+    },
    {
      "step": "installPlugin",
      "pluginData": {
        "resource": "url",
        "url": "https://github-proxy.com/proxy/?repo=woocommerce/woocommerce&release=latest&asset=woocommerce.zip"
      },
      "options": {
        "activate": true,
        "targetFolderName": "wc"
      }
    },
    {
      "step": "installPlugin",
      "pluginData": {
        "resource": "url",
        "url": "https://github-proxy.com/proxy/?repo=woocommerce/wc-smooth-generator&release=latest&asset=wc-smooth-generator.zip"
      },
      "options": {
        "activate": true,
        "targetFolderName": "wc-smooth-generator"
      }
    }
  ]
}

Let me know if this helps.

For reference: woocommerce_sort_countries is responsible for calling the problematic wc_asort_by_locale function, which causes your code to crash.

Do you find this tweak useful?

This is temporary, of course, while I look for a fix.