ruby-on-rails - Rubber : libapache2-mod-passenger の満たされていない依存関係

Question

ラバーでデプロイしようとすると、次のエラーが表示されます。

The following packages have unmet dependencies:
** [out :: staging.xxx.com] 
** [out :: staging.xxx.com] libapache2-mod-passenger : Depends:   passenger (= 1:5.0.8-1~trusty1) but it is not going to be installed
** [out :: staging.xxx.com] 
** [out :: staging.xxx.com] E
** [out :: staging.xxx.com] :
** [out :: staging.xxx.com] Unable to correct problems, you have held broken packages.

これを解決するにはどうすればよいですか?