I ran across the cmd-l tip earlier this afternoon in this article: "Faster Mac OS X 10.10 Yosemite Upgrades for Developers" (https://jimlindley.com/blog/yosemite-upgrade-homebrew-tips/).

If any of you are thinking of upgrading and use Homebrew, it sounds like it would be in your best interest to have a look. I'm holding off on upgrading until I see some early-adopter reports, but I'll certainly be following these steps when I'm ready to take the plunge.

So I guess this is a coincidental validation of MacPorts' decision to install under /opt and leave /usr/local for manually-compiled stuff.

Thanks for that. Mines been stuck saying "About a minute remaining" but sure enough cmd+L shows it's moving all my homebrew files.

protip: delete /usr/local/Cellars and posibbly LiveTex before upgrade OSX.

I'm curious, why should I delete /usr/local/Cellars?

The reason that Yosemite/Mavericks stall for a long time (although they inform users wrongly that there would be few minutes left, causing panic) is due to the copying and moving things in /usr/local/. If you have a huge /usr/local, it will take hours. Chances are you will need to remove /usr/local/Cellars and reinstall home-brew anyway. So, removing it first will save you some time.

Yup, ran into that experience myself. Viewing the log helped me see the install hadn't busted, because it also gave me the beach ball of doom around the same time. Everything was alright in the end.

I can confirm this. The installer is currently (very slowly) copying /Library/Ruby/Gems. "About a minute remaining" for ~30 mins so far.