Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires simplesamlphp/simplesamlphp-test-framework ~1.8.0 -> satisfiable by simplesamlphp/simplesamlphp-test-framework[v1.8.0, v1.8.1, 1.8.2]. - phpunit/phpunit[10.0.0, ..., 10.5.46, 11.0.0, ..., 11.5.21] require ext-xml * -> it is missing from your system. Install or enable PHP's xml extension. Alternatively you can require one of these packages that provide the extension (or parts of it): Keep in mind that the suggestions are automated and may not be valid or safe to use - nephre/php-dbus DBUS bindings for PHP language - simplesamlphp/simplesamlphp-test-framework[v1.8.0, ..., 1.8.2] require phpunit/phpunit ^10.0 || ^11.0 -> satisfiable by phpunit/phpunit[10.0.0, ..., 10.5.46, 11.0.0, ..., 11.5.21]. To enable extensions, verify that they are enabled in your .ini files: - /etc/php84/php.ini - /etc/php84/conf.d/00_ctype.ini - /etc/php84/conf.d/00_curl.ini - /etc/php84/conf.d/00_dom.ini - /etc/php84/conf.d/00_iconv.ini - /etc/php84/conf.d/00_intl.ini - /etc/php84/conf.d/00_mbstring.ini - /etc/php84/conf.d/00_openssl.ini - /etc/php84/conf.d/00_simplexml.ini - /etc/php84/conf.d/00_tokenizer.ini - /etc/php84/conf.d/00_xmlwriter.ini - /etc/php84/conf.d/01_phar.ini - /etc/php84/conf.d/10_igbinary.ini You can also run `php --ini` in a terminal to see which files are used by PHP in CLI mode. Alternatively, you can run Composer with `--ignore-platform-req=ext-xml` to temporarily ignore these required extensions.