输入 passenger-install-nginx-module后，提示
Unable to autodetect the currently active RVM gem set name. This could happen if you ran this program using ‘sudo‘ instead of ‘rvmsudo‘. When using RVM, you‘re always supposed to use ‘rvmsudo‘ instead of ‘sudo!‘.
Please try rerunning this program using ‘rvmsudo‘. If that doesn‘t help, please contact this program‘s author for support.
但是按照提示后，还是提示这样的错误。
如果有遇到这样的问题，可以试一试这样：
1、source ~/.rvm/scripts/rvm
2、? ~ rvm list
rvm rubies
ruby-2.0.0-p451 [ x86_64 ]
ruby-2.0.0-p598 [ x86_64 ]
ruby-2.1.1 [ x86_64 ]
* ruby-2.1.2 [ x86_64 ]
# => - current
# =* - current && default
# * - default
3、? ~ rvm use ruby-2.1.2
Using /Users/Mac/.rvm/gems/ruby-2.1.2
4、? ~ rvmsudo passenger-install-nginx-module
如果不出意外，就会一路安装下来，在你的
/usr/local/etc/nginx/nginx.conf文件里会多一些配置。
mac下passenger-install-nginx-module
原文：http://blog.csdn.net/iitvip/article/details/45794641