Issue #3282677: [DrupalCon] Automatic Updates beta test result

package_manager/src/ProcessFactory.php

@@ -68,14 +68,23 @@ final class ProcessFactory implements ProcessFactoryInterface {
    * {@inheritdoc}
    */
   public function create(array $command): Process {
+    $php_dir = static::getPhpDirectory();
+
+    $is_composer = $this->isComposerCommand($command);
+    // If we're about to run a Composer command, execute it directly through the
+    // PHP interpreter we're using, rather than whatever is available globally.
+    if ($is_composer) {
+      array_unshift($command, $php_dir . DIRECTORY_SEPARATOR . 'php');
+    }
+
     $process = $this->decorated->create($command);
 
     $env = $process->getEnv();
-    if ($this->isComposerCommand($command)) {
+    if ($is_composer) {
       $env['COMPOSER_HOME'] = $this->getComposerHomePath();
     }
-    // Ensure that the PHP interpreter is in the PATH.
-    $env['PATH'] = $this->getEnv('PATH') . ':' . static::getPhpDirectory();
+    // Ensure that the PHP interpreter is in the PATH as well.
+    $env['PATH'] = $this->getEnv('PATH') . ":$php_dir";
     return $process->setEnv($env);
   }