Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires benzine/core dev-main -> satisfiable by benzine/core[dev-main]. - benzine/core dev-main requires ext-apcu * -> it is missing from your system. Install or enable PHP's apcu extension. Alternatively you can require one of these packages that provide the extension (or parts of it): - empaphy/polyphill-apcu A metapackage that installs an APCU polyfill if needed, or removes it if redundant. Problem 2 - Root composer.json requires benzine/dev-tools dev-main -> satisfiable by benzine/dev-tools[dev-main]. - benzine/dev-tools dev-main requires ext-zip * -> it is missing from your system. Install or enable PHP's zip extension. Alternatively you can require one of these packages that provide the extension (or parts of it): - badpixxel/paddock Just The Paddock Project To enable extensions, verify that they are enabled in your .ini files: - /usr/local/etc/php/conf.d/docker-php-ext-sodium.ini You can also run `php --ini` in a terminal to see which files are used by PHP in CLI mode. Alternatively, you can run Composer with `--ignore-platform-req=ext-apcu --ignore-platform-req=ext-zip` to temporarily ignore these required extensions.