[mac]brew install nginx, what should I do if a compilation error occurs?

The error is as follows:

==> Downloading http://nginx.org/download/nginx-1.6.2.tar.gz

Already downloaded: /Library/Caches/Homebrew/nginx-1.6. 2.tar.gz
==> ./configure --prefix=/usr/local/Cellar/nginx/1.6.2 --with-http_ssl_module --with-pcre --with-ipv6 --sbin-path= /usr/local/Cel
+ Darwin 14.0.0 x86_64
checking for C compiler ... not found

./configure: error: C compiler clang is not found

Google it and there is an article The article mentioned that this was caused by Xcode not installing command line tools. However, I also used homebrew to install nginx on another machine and there was no problem. I checked the Xcode versions on both sides and found that there was a problem with 6.0.1. The latest 6.1.1 was OK, so I upgraded xcode and ran brew install nginx again, and it was OK

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