Error when trying to “brew link autoconf”

Question

When I try to \"brew link autoconf\" in the terminal I keep getting this error.

Error: Could not symlink file: /usr/local/Cellar/autoconf/2.69/share/emacs/site-lisp /usr

Answer 1

I had to run

chmod -R u+w /usr/local
brew link --overwrite autoconf
brew install htop