当我尝试运行命令时：
composer update drupal/core --with-dependencies
我遇到以下错误：
Your requirements could not be resolved to an installable set of packages.
Problem 1
- Installation request for drupal/drupal dev-master -> satisfiable by drupal/drupal[dev-master].
- don't install drupal/core 8.6.7|remove drupal/drupal dev-master
- Installation request for drupal/core 8.6.7 -> satisfiable by drupal/core[8.6.7].