Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires mteu/docblock-rules ^0.3 -> satisfiable by mteu/docblock-rules[0.3.0, 0.3.1]. - mteu/docblock-rules[0.3.0, ..., 0.3.1] require phpstan/phpstan ^1.10 -> found phpstan/phpstan[1.10.0, ..., 1.12.15] but it conflicts with your root composer.json require (^2.0.0). Problem 2 - Root composer.json requires mteu/zealous-stan ^0.6 -> satisfiable by mteu/zealous-stan[0.6.0, 0.6.1]. - mteu/zealous-stan 0.6.0 requires phpstan/phpstan ^1.10 -> found phpstan/phpstan[1.10.0, ..., 1.12.15] but it conflicts with your root composer.json require (^2.0.0). - mteu/zealous-stan 0.6.1 requires mteu/docblock-rules ^0.4 -> found mteu/docblock-rules[0.4.0] but it conflicts with your root composer.json require (^0.3). Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.