正常安装CocoaPods只需要在终端输入

sudo gem install cocoapods

但是不巧你遇到了错误

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-1.15.5/ext/ffi_c
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/bin/ruby -I /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0 -r ./siteconf20220121-65017-1lsof6r.rb extconf.rb
*** 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:546:in `block in try_link0'
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/tmpdir.rb:93:in `mktmpdir'
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:543:in `try_link0'
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:570:in `try_link'
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:672:in `try_ldflags'
    from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/mkmf.rb:1832:in `pkg_config'
    from extconf.rb:9: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-20/2.6.0/ffi-1.15.5/mkmf.log

extconf failed, exit code 1

Gem files will remain installed in /Library/Ruby/Gems/2.6.0/gems/ffi-1.15.5 for inspection.
Results logged to /Library/Ruby/Gems/2.6.0/extensions/universal-darwin-20/2.6.0/ffi-1.15.5/gem_make.out

接下来你要做的就是

• 安装RVM

curl -L https://get.rvm.io | bash -s stable

• 安装Ruby 2.6

rvm install ruby-2.6

如果你是M1芯片的电脑，会出现rvm command not found，此时你退出终端程序，在Finder里找到终端，右键选择显示简介，勾选使用Rosetta打开重新执行这个命令就可以了

如果遇到了下面的错误

Error running 'requirements_osx_brew_libs_install autoconf automake libtool pkg-config coreutils libyaml libksba readline zlib openssl@1.1',
please read /Users/fandong/.rvm/log/1642813404_ruby-2.6.6/package_install_autoconf_automake_libtool_pkg-config_coreutils_libyaml_libksba_readline_zlib_openssl@1.1.log
Requirements installation failed with status: 1.

我们挨个安装这些依赖

brew install autoconf

但是你可能会遇到

Warning: No available formula with the name "automake".
==> Searching for similarly named formulae...
Error: No similarly named formulae found.
==> Searching for a previously deleted formula (in the last month)...
Error: No previously deleted formula found.
==> Searching taps on GitHub...
Error: No formulae found in taps.

你需要

rm -rf /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core;
brew update

再来执行

brew install autoconf
brew install automake
brew install libtool
brew install pkg-config
brew install coreutils
brew install libyaml
brew install libksba
brew install readline
brew install zlib
brew install openssl

再来执行

rvm install ruby-2.6

然后再来执行刚开始的

sudo gem install cocoapods