我想在我的MAC上安装Drush，我按照以下步骤操作：仅在运行“ Drush”目录中的“ composer install”时出现“ https://www.drupal.org/node/1674222”错误。
我从Drush Github（https://github.com/drush-ops/drush）下载了Drush
该项目将执行自定义Drush命令，以将旧的Drupal项目设置（.yml文件）导出到新项目。
错误是有关未设置版本的问题？我发现了这个问题：“ https://drupal.stackexchange.com/questions/241431/how-do-i-resolve-this-installation-error”，我试图降级该版本，但仍然是相同的错误。
错误消息：
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Your requirements could not be resolved to an installable set of packages.
Problem 1
- Installation request for drush/drush No version set (parsed as 1.0.0) -> satisfiable by drush/drush[No version set (parsed as 1.0.0)].
- drupal/core 8.7.x-dev conflicts with drush/drush[No version set (parsed as 1.0.0)].
- Installation request for drupal/core 8.7.x-dev -> satisfiable by drupal/core[8.7.x-dev].