homebrew update on Mac: /usr/local not writable

Sometimes the most obvious solution isn’t so obvious

On my work MacBookPro laptop I issued the following Terminal Command:

brew update

it promptly came back:

 Error: /usr/local must be writable!


Doing a little web Googling and Face-2-Face conversing here in shop I learned the solution:

  • change ownership the to your current user :> whoami
sudo chown -R $(whoami) /usr/local
  • When this is successful re-execute brew update
brew update
  • When complete revert ownership of /usr/local back to root
sudo chown -R root /user/local


BAM – Homebrew update is happy, obviously 🙂

Some material for this post leveraged from github forum:  https://github.com/Homebrew/brew/issues/476

NULL Is bad : Using Optional in Java 8

Oh man has the argument against using NULL come out strong in event years.

It started with the inventor of null, Tony Hoare, calling it the Billion Dollar Mistake in 2009.

And everyone has piled on since. No one likes the NullPointerException.

See this tweet, showing everyone is jumping on this bandwagon. https://twitter.com/yegor256/status/835854965721694212

This blog author decided to take on this argument from a different angle, somewhat amusing, still thought-provoking:  Optional Method Parameters via @DZone