mac下安装cocoapods的命令：sudo gem install cocoapods
结果报错：
macdeMac-mini-3:~ admin$ sudo gem install cocoapods
Password:
ERROR: While executing gem ... (Gem::FilePermissionError)
You don't have write permissions for the /usr/bin directory.
用下面的命令指定路径就能成功安装CocoaPods了。sudo gem install -n /usr/bin/pod cocoapods
macdeMac-mini-3:~ admin$ sudo gem install -n /usr/local/bin cocoapods
Password:
Successfully installed httpclient-2.8.3
Successfully installed algoliasearch-1.27.1
Successfully installed cocoapods-core-1.8.4
Successfully installed cocoapods-1.8.4
Parsing documentation for httpclient-2.8.3
Installing ri documentation for httpclient-2.8.3
Parsing documentation for algoliasearch-1.27.1
Installing ri documentation for algoliasearch-1.27.1
Parsing documentation for cocoapods-core-1.8.4
Installing ri documentation for cocoapods-core-1.8.4
Parsing documentation for cocoapods-1.8.4
Installing ri documentation for cocoapods-1.8.4
Done installing documentation for httpclient, algoliasearch, cocoapods-core, cocoapods after 13 seconds
4 gems installed
同样，在更新Gem时也会报权限问题：
macdeMac-mini-3:~ admin$ sudo gem update --system
Password:
Updating rubygems-update
Fetching rubygems-update-3.1.2.gem
ERROR: While executing gem ... (Gem::FilePermissionError)
You don't have write permissions for the /usr/bin directory.改用下面的命令就能成功更新了。sudo gem update -n /usr/local/bin --system
macdeMac-mini-3:~ admin$ sudo gem update -n /usr/local/bin --system
Password:
Updating rubygems-update
Successfully installed rubygems-update-3.1.2
Parsing documentation for rubygems-update-3.1.2
Installing ri documentation for rubygems-update-3.1.2
Installing darkfish documentation for rubygems-update-3.1.2
Done installing documentation for rubygems-update after 89 seconds
Parsing documentation for rubygems-update-3.1.2
Done installing documentation for rubygems-update after 0 seconds
Installing RubyGems 3.1.2
NOTE: Gem::Specification#rubyforge_project= is deprecated with no replacement. It will be removed on or after 2019-12-01.
Gem::Specification#rubyforge_project= called from /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/gems/2.3.0/specifications/nokogiri-1.5.6.gemspec:22.
ERROR: While executing gem ... (Errno::EPERM)
Operation not permitted @ rb_sysopen - /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/bin/gem
macdeMac-mini-3:~ admin$ sudo gem update -n /usr/local/bin --system
NOTE: Gem::Specification#rubyforge_project= is deprecated with no replacement. It will be removed on or after 2019-12-01.
Gem::Specification#rubyforge_project= called from /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/gems/2.3.0/specifications/nokogiri-1.5.6.gemspec:22.
Latest version already installed. Done.