[m000]

Would you happen to know how to disable upgrading unrelated packages?

I often do `brew upgrade X`. Brew indeed does what is necessary to upgrade package X + deps. But then goes on and starts upgrading unrelated packages.

[jacobsenscott]

Brew does not start randomly upgrading unrelated packages.

Packages have dependencies, and those dependencies have dependencies. Try `brew deps ---tree x` to see all the dependencies for you package.

Look at `brew pin` to pin packages you don't want brew to upgrade.

Many formula are versioned. For example if you install `postgresql` it will do major upgrades of postgres as they become available, but if you install `postgres@9.6` it will only install updates to 9.6.