Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires ergebnis/phpstan-rules ^2.6.1 -> satisfiable by ergebnis/phpstan-rules[2.6.1]. - ergebnis/phpstan-rules 2.6.1 requires phpstan/phpstan ^2.0.0 -> found phpstan/phpstan[2.0.0, ..., 2.1.1] but it conflicts with your root composer.json require (^1.12.15). Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.