Same problem as in www/rubygem-rails4 ( #225428 ):
Doesn't work with the nginx flavor of rubygem-passenger but only with the default flavor which is apache. If this dependency is dropped in www/rubygem-passenger, it maybe should be dropped here as well?
A commit references this bug:
Date: Tue Mar 20 13:41:33 UTC 2018
New revision: 465087
www/redmine: Remove passenger option
It's not needed, users can install passenger and use it without the dependency.