Your requirements could not be resolved to an installable set of packages. Problem 1 - phpunit/phpunit[9.0.0, ..., 9.2.5] require phpspec/prophecy ^1.8.1 -> found phpspec/prophecy[1.8.1, ..., v1.18.0] but the package is fixed to v1.7.0 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command. - phpunit/phpunit 9.2.6 requires phpspec/prophecy ^1.10.3 -> found phpspec/prophecy[v1.10.3, ..., v1.18.0] but the package is fixed to v1.7.0 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command. - phpunit/phpunit[9.3.0, ..., 9.4.0] require phpspec/prophecy ^1.11.1 -> found phpspec/prophecy[1.11.1, ..., v1.18.0] but the package is fixed to v1.7.0 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command. - phpunit/phpunit[9.4.1, ..., 9.5.22] require phpspec/prophecy ^1.12.1 -> found phpspec/prophecy[1.12.1, ..., v1.18.0] but the package is fixed to v1.7.0 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command. - phpunit/phpunit[9.5.23, ..., 9.5.24] require sebastian/comparator ^4.0.5 -> found sebastian/comparator[4.0.5, 4.0.6, 4.0.7, 4.0.8] but these were not loaded, likely because it conflicts with another require. - phpunit/phpunit[9.5.25, ..., 9.6.17] require sebastian/comparator ^4.0.8 -> found sebastian/comparator[4.0.8] but these were not loaded, likely because it conflicts with another require. - Root composer.json requires phpunit/phpunit ^9.0.0 -> satisfiable by phpunit/phpunit[9.0.0, ..., 9.6.17]. Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.