Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires psalm/plugin-phpunit ^0.19 -> satisfiable by psalm/plugin-phpunit[0.19.0]. - phpunit/phpunit[11.4.2, ..., 11.4.3] require phpunit/php-code-coverage ^11.0.7 -> satisfiable by phpunit/php-code-coverage[11.0.7]. - phpunit/phpunit[11.3.2, ..., 11.4.1] require phpunit/php-code-coverage ^11.0.6 -> satisfiable by phpunit/php-code-coverage[11.0.6, 11.0.7]. - phpunit/phpunit[11.2.7, ..., 11.3.1] require phpunit/php-code-coverage ^11.0.5 -> satisfiable by phpunit/php-code-coverage[11.0.5, 11.0.6, 11.0.7]. - phpunit/phpunit[11.0.0, ..., 11.2.6] require phpunit/php-code-coverage ^11.0 -> satisfiable by phpunit/php-code-coverage[11.0.0, ..., 11.0.7]. - phpunit/php-code-coverage 11.0.7 requires nikic/php-parser ^5.3.1 -> satisfiable by nikic/php-parser[v5.3.1]. - phpunit/php-code-coverage 11.0.6 requires nikic/php-parser ^5.1.0 -> satisfiable by nikic/php-parser[v5.1.0, v5.2.0, v5.3.0, v5.3.1]. - phpunit/php-code-coverage[11.0.0, ..., 11.0.5] require nikic/php-parser ^5.0 -> satisfiable by nikic/php-parser[v5.0.0, ..., v5.3.1]. - Conclusion: don't install nikic/php-parser v5.3.1 (conflict analysis result) - Root composer.json requires phpunit/phpunit ^11.0 -> satisfiable by phpunit/phpunit[11.0.0, ..., 11.4.3]. Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.