Your requirements could not be resolved to an installable set of packages. Problem 1 - a9f/typo3-fractor[dev-main, 0.4.x-dev] require a9f/fractor ^0.4 -> satisfiable by a9f/fractor[v0.4.0] from composer repo (https://repo.packagist.org) but a9f/fractor[dev-main, 0.3.x-dev (alias of dev-main)] from path repo (../packages/*) has higher repository priority. The packages from the higher priority repository do not match your constraint and are therefore not installable. That repository is canonical so the lower priority repo's packages are not installable. See https://getcomposer.org/repoprio for details and assistance. - a9f/typo3-fractor 0.4.x-dev is an alias of a9f/typo3-fractor dev-main and thus requires it to be installed too. - Root composer.json requires a9f/typo3-fractor @dev -> satisfiable by a9f/typo3-fractor[dev-main, 0.4.x-dev (alias of dev-main)].