Homebrew fatal: needed a single revision (MacOs Sierra)

Question

Not sure if this problem is related to upgrading to MacOs Sierra, but since that moment this error occurs when I run \'brew update\'

→ brew update
Checking          


        

Answer 1

I had the same problem after upgrading to Sierra.

In addition to brew --prefix, which displays Homebrew’s install path, there’s also brew --repository, which displays where it’s .git directory is located.

man brew says that claims that “for standard installs, the prefix and repository are the same directory”. Either the man page is out of date or my install isn’t “standard”, but my prefix is /usr/local and my repository is /usr/local/Homebrew.

Using the same command but with cd $(brew --repository) worked for me:

cd $(brew --repository) && git fetch && git reset --hard origin/master

Answer 2

Nothing really worked for me, I had to resort to uninstalling and reinstalling Brew:

# change to home directory to avoid other errors later
cd ~

# uninstall brew
rm -rf /usr/local/Cellar /usr/local/.git && cd ~ && brew cleanup

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

Answer 3

The accepted answer didn't work for me. What worked was uninstalling homebrew and reinstalling it:

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