Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires boesing/psalm-plugin-stringf ^1.4 -> satisfiable by boesing/psalm-plugin-stringf[1.4.0]. - boesing/psalm-plugin-stringf 1.4.0 requires php ^7.4 || ~8.0.0 || ~8.1.0 || ~8.2.0 -> your php version (8.3.0RC3) does not satisfy that requirement. Problem 2 - Root composer.json requires laminas/laminas-cli ^1.8 -> satisfiable by laminas/laminas-cli[1.8.0]. - laminas/laminas-cli 1.8.0 requires php ~8.0.0 || ~8.1.0 || ~8.2.0 -> your php version (8.3.0RC3) does not satisfy that requirement. Problem 3 - Root composer.json requires laminas/laminas-container-config-test ^1.0 -> satisfiable by laminas/laminas-container-config-test[1.0.0]. - laminas/laminas-container-config-test 1.0.0 requires php ~8.1.0 || ~8.2.0 -> your php version (8.3.0RC3) does not satisfy that requirement. Problem 4 - Root composer.json requires lctrs/psalm-psr-container-plugin ^1.9 -> satisfiable by lctrs/psalm-psr-container-plugin[1.9.0]. - lctrs/psalm-psr-container-plugin 1.9.0 requires php >=8.0.2 <8.3.0 -> your php version (8.3.0RC3) does not satisfy that requirement. Problem 5 - friendsofphp/proxy-manager-lts v1.0.0 requires laminas/laminas-code ^3.4.1 -> satisfiable by laminas/laminas-code[3.4.1, 3.5.0, 3.5.1]. - friendsofphp/proxy-manager-lts[v1.0.2, ..., v1.0.16] require laminas/laminas-code ~3.4.1|^4.0 -> satisfiable by laminas/laminas-code[3.4.1, 4.0.0, ..., 4.12.0]. - friendsofphp/proxy-manager-lts v1.0.1 requires laminas/laminas-code ^3.4.1|^4.0 -> satisfiable by laminas/laminas-code[3.4.1, 3.5.0, 3.5.1, 4.0.0, ..., 4.12.0]. - laminas/laminas-code[3.5.0, ..., 3.5.1] require php ^7.3 || ~8.0.0 -> your php version (8.3.0RC3) does not satisfy that requirement. - laminas/laminas-code 3.4.1 requires php ^7.1 -> your php version (8.3.0RC3) does not satisfy that requirement. - laminas/laminas-code[4.0.0, ..., 4.4.3] require php ^7.4 || ~8.0.0 -> your php version (8.3.0RC3) does not satisfy that requirement. - laminas/laminas-code[4.5.0, ..., 4.7.1] require php >=7.4, <8.2 -> your php version (8.3.0RC3) does not satisfy that requirement. - laminas/laminas-code[4.8.0, ..., 4.12.0] require php ~8.1.0 || ~8.2.0 -> your php version (8.3.0RC3) does not satisfy that requirement. - Root composer.json requires friendsofphp/proxy-manager-lts ^1 -> satisfiable by friendsofphp/proxy-manager-lts[v1.0.0, ..., v1.0.16]. Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.