brew Install encounter error /usr/local/share/texinfo is not writable ==&gt; Installing ffmpeg dependency: texi2html
==&gt; Downloading https://homebrew.bintray.com/bottles/texi2html-5.0.high_sierra.b
==&gt; Downloading from https://akamai.bintray.com/52/5259ab2074f122f4725058d247723
######################################################################## 100.0%
==&gt; Pouring texi2html-5.0.high_sierra.bottle.1.tar.gz
Error: The `brew link` step did not complete successfully
The formula built, but is not symlinked into /usr/local
Could not symlink share/texinfo/html
/usr/local/share/texinfo is not writable.


any ideas?
Try running the command:

sudo chown -R `whoami`:admin /usr/local/share/texinfo


and reattempting the installation.