Updating Homebrew for macOS

Updating brew.sh for macOS is a fairly easy and trivial task (you can use my brewup script from here to make it even simpler), but sometimes things go south and the update process ends with a somewhat cryptic error like this:

==> Postinstalling node

Warning: The post-install step did not complete successfully

You can try again using `brew postinstall node`

Running brew doctor could help identify the culprit and it usually ends up being a Permission denied error – remember the time you tried to issue some commands related to brew / node / npm that began with the magical word sudo? Well, it turns out those files affected by it are now untouchable and that’s why brew fails to update.

To solve this permission denied error, issue the following in a terminal session:

sudo chown -R $(whoami):admin /usr/local/lib/node_modules/