安装cocoa pods时，
在命令行中输入：
安装：sudo gem install cocoapods报Operation not permitted - /usr/bin/xcodeproj这个错误，解决办法为：
用
sudo gem install -n /usr/local/bin cocoapods --pre
这段命令代替
sudo gem install cocoapods
然后：
pod install --verbose --no-repo-update
Preparing
这段代替 pod update 或者 pod install
就完美解决了
安装cocoapods的步骤为：
1、更新ruby
sudo gem update --system
2、
更换Ruby镜像－－淘宝的那个镜像(https://ruby.taobao.org/ )已经不可用了。官方的需要FQ。所以我们现在用最新支持的ruby镜像(https://gems.ruby-china.org/)
需要的命令行：
gem sources --remove https://rubygems.org/
gem sources -a https://gems.ruby-china.org/
gem sources -l （用来检查使用替换镜像位置成功）
出现
*** CURRENT SOURCES ***
https://gems.ruby-china.org/
则说明成功了3、安装cocoapods 命令行： sudo gem install -n /usr/local/bin cocoapods --pre
终端打印：
MacintoshdeiMac:~ Mac$ sudo gem install -n /usr/local/bin cocoapods --pre
ERROR: SSL verification error at depth 1: unable to get local issuer certificate (20)
ERROR: You must add /O=Digital Signature Trust Co./CN=DST Root CA X3 to your local trusted store
ERROR: SSL verification error at depth 2: self signed certificate in certificate chain (19)
ERROR: Root certificate is not trusted (/C=US/O=GeoTrust Inc./CN=GeoTrust Global CA)
Successfully installed xcodeproj-1.4.2
Fetching: ruby-macho-0.2.6.gem (100%)
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Successfully installed cocoapods-try-1.1.0
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Successfully installed cocoapods-trunk-1.1.2
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Successfully installed cocoapods-search-1.0.0
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Successfully installed cocoapods-plugins-1.0.0
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Successfully installed cocoapods-downloader-1.1.3
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Successfully installed cocoapods-deintegrate-1.0.1
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Successfully installed fuzzy_match-2.0.4
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Successfully installed cocoapods-core-1.2.0.beta.1
Fetching: cocoapods-1.2.0.beta.1.gem (100%)
Successfully installed cocoapods-1.2.0.beta.1
Parsing documentation for xcodeproj-1.4.2
Installing ri documentation for xcodeproj-1.4.2
Parsing documentation for ruby-macho-0.2.6
Installing ri documentation for ruby-macho-0.2.6
Parsing documentation for nap-1.1.0
Installing ri documentation for nap-1.1.0
Parsing documentation for molinillo-0.5.4
Installing ri documentation for molinillo-0.5.4
Parsing documentation for gh_inspector-1.0.2
Installing ri documentation for gh_inspector-1.0.2
Parsing documentation for fourflusher-2.0.1
Installing ri documentation for fourflusher-2.0.1
Parsing documentation for escape-0.0.4
Installing ri documentation for escape-0.0.4
Parsing documentation for cocoapods-try-1.1.0
Installing ri documentation for cocoapods-try-1.1.0
Parsing documentation for netrc-0.7.8
Installing ri documentation for netrc-0.7.8
Parsing documentation for cocoapods-trunk-1.1.2
Installing ri documentation for cocoapods-trunk-1.1.2
Parsing documentation for cocoapods-stats-1.0.0
Installing ri documentation for cocoapods-stats-1.0.0
Parsing documentation for cocoapods-search-1.0.0
Installing ri documentation for cocoapods-search-1.0.0
Parsing documentation for cocoapods-plugins-1.0.0
Installing ri documentation for cocoapods-plugins-1.0.0
Parsing documentation for cocoapods-downloader-1.1.3
Installing ri documentation for cocoapods-downloader-1.1.3
Parsing documentation for cocoapods-deintegrate-1.0.1
Installing ri documentation for cocoapods-deintegrate-1.0.1
Parsing documentation for fuzzy_match-2.0.4
Installing ri documentation for fuzzy_match-2.0.4
Parsing documentation for cocoapods-core-1.2.0.beta.1
Installing ri documentation for cocoapods-core-1.2.0.beta.1
Parsing documentation for cocoapods-1.2.0.beta.1
Installing ri documentation for cocoapods-1.2.0.beta.1
18 gems installed
到此安装成功！