参考：https://www.jianshu.com/p/57b599e48ba2
Error fetching https://ruby.taobao.org/:RubySass淘宝镜源无效解决
ERROR: Error installing cocoapods: ERROR: Failed to build gem native extension
安装cocoapods的步骤
安装
第一步：
sudo gem install cocoapods
注释：如果你的mac系统是10.11，则使用下面这个命令
sudo gem install -n /usr/local/bin/ cocoapods
第二步：
pod setup
注释：pod setup在执行时，会输出Setting up CocoaPods master repo，会等待很长时间，可以使用 cd ~/.cocoapods进入此目录下，然后用du -sh *来查看下载进度
错误处理
1.错误情况1
sudo gem install -n /usr/local/bin/ cocoapods
Building native extensions. This could take a while...
ERROR: Error installing cocoapods:
ERROR: Failed to build gem native extension.
current directory: /Library/Ruby/Gems/2.6.0/gems/ffi-1.15.0/ext/ffi_c
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/bin/ruby -I /Library/Ruby/Site/2.6.0 -r ./siteconf20210311-12525-uvd6nc.rb extconf.rb
checking for ffi.h... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers. Check the mkmf.log file for more details. You may
need configuration options.
Provided configuration options:
--with-opt-dir
--without-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/bin/$(RUBY_BASE_NAME)
--with-ffi_c-dir
--without-ffi_c-dir
--with-ffi_c-include
--without-ffi_c-include=${ffi_c-dir}/include
--with-ffi_c-lib
--without-ffi_c-lib=${ffi_c-dir}/lib
--enable-system-libffi
--disable-system-libffi
--with-libffi-config
--without-libffi-config
--with-pkg-config
--without-pkg-config
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:467:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:585:in `block in try_compile'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:534:in `with_werror'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:585:in `try_compile'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:1109:in `block in have_header'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:959:in `block in checking_for'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:361:in `block (2 levels) in postpone'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:331:in `open'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:361:in `block in postpone'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:331:in `open'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:357:in `postpone'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:958:in `checking_for'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:1108:in `have_header'
from extconf.rb:10:in `system_libffi_usable?'
from extconf.rb:42:in `<main>'
To see why this extension failed to compile, please check the mkmf.log which can be found here:
/Library/Ruby/Gems/2.6.0/extensions/universal-darwin-19/2.6.0/ffi-1.15.0/mkmf.log
extconf failed, exit code 1
Gem files will remain installed in /Library/Ruby/Gems/2.6.0/gems/ffi-1.15.0 for inspection.
Results logged to /Library/Ruby/Gems/2.6.0/extensions/universal-darwin-19/2.6.0/ffi-1.15.0/gem_make.out
试过的解决方法：
移除现有的Ruby
gem sources -a https://ruby.taobao.org/
验证当前ruby版本
$gem sources -l
成功后提示：
*** CURRENT SOURCES ***
https://ruby.taobao.org/
结果又报错：
ERROR: SSL verification error at depth 0: ok (0)
Error fetching https://ruby.taobao.org/:
SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed (certificate rejected) (https://ruby.taobao.org/specs.4.8.gz)
解决方法：
移除掉rubygems.org
gem sources --remove https://rubygems.org/
添加镜像源
gem sources -a https://gems.ruby-china.com/
检查当前Source列表
gem sources
成功更新ruby;
之后继续执行：
sudo gem install -n /usr/local/bin/ cocoapods
还是报错，同样的错误。
2.解决方法2
brew cleanup -d -v
brew install cocoapods
Note: If you see failed to link then run brew link cocoapods
成功安装
Warning: Treating cocoapods as a formula. For the cask, use homebrew/cask/cocoapods
==> Downloading https://mirrors.ustc.edu.cn/homebrew-bottles/bottles/cocoapods-1
######################################################################## 100.0%
==> Pouring cocoapods-1.10.1.catalina.bottle.tar.gz
Error: The `brew link` step did not complete successfully
The formula built, but is not symlinked into /usr/local
Could not symlink bin/xcodeproj
Target /usr/local/bin/xcodeproj
already exists. You may want to remove it:
rm '/usr/local/bin/xcodeproj'
To force the link and overwrite all conflicting files:
brew link --overwrite cocoapods
To list all files that would be deleted:
brew link --overwrite --dry-run cocoapods
Possible conflicting files are:
/usr/local/bin/xcodeproj
==> Summary
🍺 /usr/local/Cellar/cocoapods/1.10.1: 13,132 files, 30.4MB
