Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires charonlab/coding-standard 1.2.x-dev (exact version match), found charonlab/coding-standard[dev-master, 1.0.0, 1.0.1, 1.1.0, 1.2.0] but it does not match the constraint. Problem 2 - Root composer.json requires phpunit/phpunit 11.1.x-dev (exact version match), found phpunit/phpunit[dev-do-not-cache-test-double-declarations, dev-scope-internal-units-of-code, dev-destroy-testcase-objects-after-execution, dev-main, dev-issue-4321/new-xml-logfile-format, dev-issue-5775/emit-events-for-errors-triggered-in-data-provider-methods, dev-phpunit-12/test-double-cleanup, dev-phpunit-12/annotations-cleanup, 3.7.0, ..., 3.7.38, 4.0.0, ..., 4.8.36, 5.0.0, ..., 5.7.27, 6.0.0, ..., 6.5.14, 7.0.0, ..., 7.5.20, 8.0.0, ..., 8.5.x-dev, 9.0.0, ..., 9.6.x-dev, 10.0.0, ..., 10.5.x-dev, 11.0.0, ..., 11.3.x-dev (alias of dev-main)] but it does not match the constraint.