我正在尝试仅更新单个软件包及其依赖项。当我尝试空运行时，它似乎正确列出了所有需要更新的软件包：
> composer update drupal/core --with-dependencies --dry-run
Loading composer repositories with package information
Updating dependencies (including require-dev)
Package operations: 0 installs, 17 updates, 0 removals
- Updating guzzlehttp/psr7 (1.3.1) to guzzlehttp/psr7 (1.4.2)
- Updating guzzlehttp/guzzle (6.2.2) to guzzlehttp/guzzle (6.2.3)
- Updating symfony/class-loader (v2.8.17) to symfony/class-loader (v2.8.18)
- Updating symfony/debug (v2.8.17) to symfony/debug (v2.8.18)
- Updating symfony/console (v2.8.17) to symfony/console (v2.8.18)
- Updating symfony/dependency-injection (v2.8.17) to symfony/dependency-injection (v2.8.18)
- Updating symfony/http-foundation (v2.8.17) to symfony/http-foundation (v2.8.18)
- Updating symfony/event-dispatcher (v2.8.17) to symfony/event-dispatcher …composer-php ×1