nginx repomd.xml 404找不到

我按照http://wiki.nginx.org/Install中的规定设置了nginx存储库

[nginx] name=nginx repo baseurl=http://nginx.org/packages/rhel/$releasever/$basearch/ gpgcheck=0 enabled=1 

当我尝试安装php-fpm时，出现以下错误

 http://nginx.org/packages/rhel/6Server/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found" Trying other mirror. Error: Cannot retrieve repository metadata (repomd.xml) for repository: nginx. Please verify its path and try again 

什么是我可以替代的另一个稳定的baseurl？

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 Due to differences between how CentOS, RHEL, and Scientific Linux populate the $releasever variable, it is necessary to manually replace $releasever with either "5" (for 5.x) or "6" (for 6.x), depending upon your OS version.