Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires platine-php/stdlib 1.0.x-dev (exact version match), found platine-php/stdlib[dev-develop] but it does not match the constraint. Problem 2 - Root composer.json requires platine-php/dev 1.0.x-dev (exact version match), found platine-php/dev[dev-develop, v1.0.0] but it does not match the constraint.