homebrew as a package manager for certain web development app. To keep
brew up-to-date I run
update brew every couple of days and also run
brew doctor. Usually, this is fine and
brew tells me I'm ready to brew.
Every now and then, however, I get the following error:
Warning: /usr/local/etc isn't writable.
This can happen if you "sudo make install" software that isn't managed by by Homebrew. If a formula tries to write a file to this directory, the install will fail during the link step.
You should probably
Warning: The /usr/local directory is not writable. Even if this directory was writable when you installed Homebrew, other software may change permissions on this directory. Some versions of the "InstantOn" component of Airfoil are known to do this.
You should probably change the ownership and permissions of /usr/local back to your user account.
It's easy enough to reset the permissions back to my username. Afterwards
brew seems to be fine.
But what is causing this to happen?
Is there a log that shows what is causing the permissions to change?