I started upgrading from version 2.3.3 to 2.3.5, but Magento crashed during the Composer update with the following error:PHP Version 7.2.x on Ubuntu 18.04
- Installing laminas/laminas-dependency-plugin (1.0.3): Downloading (100%)PHP Fatal error: Uncaught Error: Undefined class constant 'PRE_COMMAND_RUN' in /var/www/html/erag.swiss/public_html/vendor/laminas/laminas-dependency-plugin/src/DependencyRewriterPlugin.php:63Stack trace:#0 phar:///usr/local/bin/composer/src/Composer/EventDispatcher/EventDispatcher.php(378): Laminas\DependencyPlugin\DependencyRewriterPlugin::getSubscribedEvents()#1 phar:///usr/local/bin/composer/src/Composer/Plugin/PluginManager.php(239): Composer\EventDispatcher\EventDispatcher->addSubscriber(Object(Laminas\DependencyPlugin\DependencyRewriterPlugin))#2 phar:///usr/local/bin/composer/src/Composer/Plugin/PluginManager.php(205): Composer\Plugin\PluginManager->addPlugin(Object(Laminas\DependencyPlugin\DependencyRewriterPlugin))#3 phar:///usr/local/bin/composer/src/Composer/Installer/PluginInstaller.php(63): Composer\Plugin\PluginManager->registerPackage(Object(Composer\Package\CompletePackage), true)#4 phar:///usr/local/bin/composer/src/Composer/Installer/InstallationManager.php(173): Composer\Installer\PluginInstaller->in in /var/www/html/erag.swiss/public_html/vendor/laminas/laminas-dependency-plugin/src/DependencyRewriterPlugin.php on line 63
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I understand the problem you are facing !
Yesterday i i did try the same and facing the same error.
Solution is you will require to update your composer first !
Currently your composer might have version 1.6.5 or upper, So first update your composer version by running following command from the root user.
It will update composer to latest version which is 1.10.5 something.
Once that is done - Run your commands again to update the Magento version, it will not gives you the error and it will works for you.
Hope it helps !
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