1.命令安裝

brew install binutils

出現以下錯誤：

See `config.log' for more details.
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require': no implicit conversion of nil into String (TypeError)
	from /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
	from /usr/local/Library/ENV/4.3/gcc-4.2:4:in `<main>'

READ THIS: https://git.io/brew-troubleshooting

/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/open-uri.rb:359:in `open_http': 422 Unprocessable Entity (GitHub::Error)
	from /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/open-uri.rb:737:in `buffer_open'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/open-uri.rb:212:in `block in open_loop'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/open-uri.rb:210:in `catch'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/open-uri.rb:210:in `open_loop'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/open-uri.rb:151:in `open_uri'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/open-uri.rb:717:in `open'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/open-uri.rb:31:in `open'
	from /usr/local/Library/Homebrew/utils.rb:505:in `open'
	from /usr/local/Library/Homebrew/utils.rb:535:in `issues_matching'
	from /usr/local/Library/Homebrew/utils.rb:567:in `issues_for_formula'
	from /usr/local/Library/Homebrew/exceptions.rb:222:in `fetch_issues'
	from /usr/local/Library/Homebrew/exceptions.rb:218:in `issues'
	from /usr/local/Library/Homebrew/exceptions.rb:261:in `dump'
	from /usr/local/Library/brew.rb:186:in `rescue in <main>'
	from /usr/local/Library/brew.rb:76:in `<main>'
 

隨後又執行：

brew update

出現以下錯誤：

Error: The /usr/local directory is not writable.
Even if this directory was writable when you installed Homebrew, other
software may change permissions on this directory. Some versions of the
"InstantOn" component of Airfoil or running Cocktail cleanup/optimizations
are known to do this.

You should probably change the ownership and permissions of /usr/local
back to your user account.
  sudo chown -R $(whoami):admin /usr/local
 

接著又執行：

sudo chown -R $(whoami):admin /usr/local

又出現：chown: /usr/local: Operation not permitted

2.解決辦法

1. 先解除安裝ruby

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/uninstall)"

2. 再安裝ruby

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
 

3. 安裝binutils

brew install binutils