报错：Failed to upgrade Homebrew Po

Last login: Tue Aug 25 01:06:49 on ttys000
david@daviddeMBP ~ % brew install expect
==> Downloading https://homebrew.bintray.com/bottles-portable-ruby/portable-ruby-2.6.3_2.yosemite.bottle.tar.gz
Already downloaded: /Users/david/Library/Caches/Homebrew/portable-ruby-2.6.3_2.yosemite.bottle.tar.gz
Error: Checksum mismatch.
Expected: b065e5e3783954f3e65d8d3a6377ca51649bfcfa21b356b0dd70490f74c6bd86
  Actual: be55b6e9a8b2f2daa3fe6bcf79c5c5f27890c3867a78c9c337bc2b290cf268a8
 Archive: /Users/david/Library/Caches/Homebrew/portable-ruby-2.6.3_2.yosemite.bottle.tar.gz
To retry an incomplete download, remove the file above.
Error: Failed to upgrade Homebrew Portable Ruby!

解决方法：rm -rf 指定删除文件（上述:/Users/david/Library/Caches/Homebrew/portable-ruby-2.6.3_2.yosemite.bottle.tar.gz）