What's the recommendation if you're using command/shell utilities on upgrading vs. clean install from Yosemite to El Capitan? I usually do a clean install, but would an upgrade be advisable?
The one annoyance I've encountered is that the installer will move everything in /usr/local out of the way before doing the upgrade and moving it back. If you have a large Homebrew install, it will be much faster to move the directory first and restore it later rather than waiting for the file-by-file copy to complete, even on when using SSDs.
There was the odd infuriating bug (I'm not convinced it's tested as thoroughly as Windows is...), but overall it was fairly trouble free and the smooth upgrade process played a part in my decision to buy another. It certainly wasn't the price, at any rate.
This can be a significant point. I thought my computer was bricked when I did one of the previous upgrades (maybe Mavericks?) and the upgrade took something like 14 hours (with no change in the progress bar).
Always a clean install. Always.
Whether it's NT4 or Win95 or Classic Mac or Snow Leopard or Mavericks ... always, always do a wipe and a clean install.
Life is too short to deal with the alternative.
It's potentially contradictory: the alternative is upgrading your OS and find pretty much everything where you left it, instead of having to reinstall everything. I.e. life is too short to spend time reinstalling everything.
Surely, it's an opportunity to do some cleanup of unused stuff, but otherwise, I haven't had a lot of problems upgrading OS X. (nothing memorable at least)
I've had 2 or 3 issues where old config was the root cause, but those are few and far between. I might be an outlier, but it's always just "worked for me".
Edit: oops!
Of course, you meant OS 10.2 (a.k.a. Jaguar). Otherwise, it's not that impressive ;-)
Of course you still do a backup before in case the universe blows up.
Upgrading XCode, updating homebrew, and chown-ing /usr/local seemed to fix everything.
brew doctor