diff -up ./bin/composer.rpm ./bin/composer
--- ./bin/composer.rpm	2024-10-03 07:10:57.000000000 +0200
+++ ./bin/composer	2024-10-03 07:11:10.751092365 +0200
@@ -16,7 +16,7 @@ if (PHP_VERSION_ID < 70205) {
 }
 
 setlocale(LC_ALL, 'C');
-require __DIR__.'/../src/bootstrap.php';
+require '/usr/share/composer/src/bootstrap.php';
 
 use Composer\Console\Application;
 use Composer\XdebugHandler\XdebugHandler;
diff -up ./src/Composer/InstalledVersions.php.rpm ./src/Composer/InstalledVersions.php
--- ./src/Composer/InstalledVersions.php.rpm	2024-10-03 07:10:57.000000000 +0200
+++ ./src/Composer/InstalledVersions.php	2024-10-03 07:11:10.752092401 +0200
@@ -266,7 +266,7 @@ class InstalledVersions
         if (null === self::$installed) {
             // only require the installed.php file if this file is loaded from its dumped location,
             // and not from its source location in the composer/composer package, see https://github.com/composer/composer/issues/9937
-            if (substr(__DIR__, -8, 1) !== 'C') {
+            if (substr(__DIR__, -8, 1) !== 'C' && is_file(__DIR__ . '/installed.php')) {
                 self::$installed = include __DIR__ . '/installed.php';
             } else {
                 self::$installed = array();
@@ -341,7 +341,7 @@ class InstalledVersions
         if (null === self::$installed) {
             // only require the installed.php file if this file is loaded from its dumped location,
             // and not from its source location in the composer/composer package, see https://github.com/composer/composer/issues/9937
-            if (substr(__DIR__, -8, 1) !== 'C') {
+            if (substr(__DIR__, -8, 1) !== 'C' && is_file(__DIR__ . '/installed.php')) {
                 /** @var array{root: array{name: string, pretty_version: string, version: string, reference: string|null, type: string, install_path: string, aliases: string[], dev: bool}, versions: array<string, array{pretty_version?: string, version?: string, reference?: string|null, type?: string, install_path?: string, aliases?: string[], dev_requirement: bool, replaced?: string[], provided?: string[]}>} $required */
                 $required = require __DIR__ . '/installed.php';
                 self::$installed = $required;
diff -up ./vendor/composer/ca-bundle/src/CaBundle.php.rpm ./vendor/composer/ca-bundle/src/CaBundle.php
--- ./vendor/composer/ca-bundle/src/CaBundle.php.rpm	2024-09-25 09:49:53.000000000 +0200
+++ ./vendor/composer/ca-bundle/src/CaBundle.php	2024-10-03 07:11:10.752092401 +0200
@@ -125,7 +125,7 @@ class CaBundle
      */
     public static function getBundledCaBundlePath()
     {
-        $caBundleFile = __DIR__.'/../res/cacert.pem';
+        $caBundleFile = '/etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem'; // System CA, always
 
         // cURL does not understand 'phar://' paths
         // see https://github.com/composer/ca-bundle/issues/10
diff -up ./src/Composer/Command/SelfUpdateCommand.php.rpm ./src/Composer/Command/SelfUpdateCommand.php
--- ./src/Composer/Command/SelfUpdateCommand.php.rpm	2026-05-28 14:51:24.953172177 +0200
+++ ./src/Composer/Command/SelfUpdateCommand.php	2026-05-28 14:51:30.174907909 +0200
@@ -86,7 +86,8 @@ EOT
                 $output->writeln('<comment>To update Composer, download a composer.phar from https://getcomposer.org and then run `composer.phar update composer/composer` in your project.</comment>');
             } else {
                 $output->writeln('<error>This instance of Composer does not have the self-update command.</error>');
-                $output->writeln('<comment>This could be due to a number of reasons, such as Composer being installed as a system package on your OS, or Composer being installed as a package in the current project.</comment>');
+                $output->writeln('<comment>Composer is installed as a system package on your OS.</comment>');
+                $output->writeln('<comment>Update the composer RPM using the package manager (dnf).</comment>');
             }
 
             return 1;