Repetition error

$ brewTraceback (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:37:in `<top (required)>' 8: The from/System/Library/Frameworks/Ruby framework Versions / 2.6 / usr/lib/Ruby/server/rubygems/core_ext/kernel_require rb: 54: in  `require' 7: The from/System/Library/Frameworks/Ruby framework Versions / 2.6 / usr/lib/Ruby/server/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)Copy the code

The solution

Big Sur does not work with old Homebrew. Update to new Homebrew to use:

First, update the reset command:

$ brew update-reset
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Execute after completion:

$ brew update
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Finally, exit the terminal and open it again to resume the BREW command and all previously installed command tools.