Your lock file does not contain a compatible set of packages. Please run composer update. Problem 1 - Root composer.json requires PHP extension ext-iconv * but it is missing from your system. Install or enable PHP's iconv extension. Problem 2 - phpdocumentor/guides-theme-rst is locked to version dev-main and an update of this package was not requested. - phpdocumentor/guides-theme-rst dev-main requires ext-iconv * -> it is missing from your system. Install or enable PHP's iconv extension. Problem 3 - phpdocumentor/guides-theme-rst is locked to version 2.x-dev and an update of this package was not requested. - phpdocumentor/guides-theme-rst dev-main requires ext-iconv * -> it is missing from your system. Install or enable PHP's iconv extension. - phpdocumentor/guides-theme-rst 2.x-dev is an alias of phpdocumentor/guides-theme-rst dev-main and thus requires it to be installed too. To enable extensions, verify that they are enabled in your .ini files: - /etc/php/8.1/cli/php.ini - /etc/php/8.1/cli/conf.d/15-xml.ini - /etc/php/8.1/cli/conf.d/20-ctype.ini - /etc/php/8.1/cli/conf.d/20-dom.ini - /etc/php/8.1/cli/conf.d/20-fileinfo.ini - /etc/php/8.1/cli/conf.d/20-mbstring.ini - /etc/php/8.1/cli/conf.d/20-phar.ini - /etc/php/8.1/cli/conf.d/20-simplexml.ini - /etc/php/8.1/cli/conf.d/20-tokenizer.ini - /etc/php/8.1/cli/conf.d/20-xmlwriter.ini - /etc/php/8.1/cli/conf.d/99-pecl.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-iconv` to temporarily ignore these required extensions.