[macOS] error when brew updating

I want to update the brew, then run 

brew update

but unluckly, i got these error

/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
/usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
Error: update-report should not be called directly!

Here is the solution

brew upgrade

That is all! You can find another solution here: https://discuss.circleci.com/t/brew-update-command-fails/5211/4

Have fun with macOS!