今天兴致勃勃的升级成macOS 11.0后，给电脑安装onedrive的时候，发现运行brew任何命令都会出现以下错误。
zy-root $ brew cask install onedrive
Traceback (most recent call last):
11: from /usr/local/Homebrew/Library/Homebrew/brew.rb:23:in `<main>'
10: from /usr/local/Homebrew/Library/Homebrew/brew.rb:23:in `require_relative'
9: from /usr/local/Homebrew/Library/Homebrew/global.rb:29:in `<top (required)>'
8: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
7: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
6: from /usr/local/Homebrew/Library/Homebrew/os.rb:3:in `<top (required)>'
5: from /usr/local/Homebrew/Library/Homebrew/os.rb:21:in `<module:OS>'
4: from /usr/local/Homebrew/Library/Homebrew/os/mac.rb:58:in `prerelease?'
3: from /usr/local/Homebrew/Library/Homebrew/os/mac.rb:24:in `version'
2: from /usr/local/Homebrew/Library/Homebrew/os/mac.rb:24:in `new'
1: from /usr/local/Homebrew/Library/Homebrew/os/mac/version.rb:26:in `initialize'
/usr/local/Homebrew/Library/Homebrew/version.rb:368:in `initialize': Version value must be a string; got a NilClass () (TypeError)
解决办法：
/usr/local/Homebrew/Library/Homebrew/version.rb中的368行出现问题，因为homebrew只能安装在正式版中运行，测试版本任何命令都是不能运行的。
我们用IDEA打开version.rb文件，只需要将其中的代码修改为以下形式：
def initialize(val)
# raise TypeError, "Version value must be a string; got a #{val.class} (#{val})" unless val.respond_to?(:to_str)
@version = '10.14.6' 或者其他任何macos正式版本即可，推荐使用10.14.6版本
end
