A lot of Homebrew packages are pre-compiled binaries ("bottles" produced by Homebrew) that are pretty much just downloaded and untarred onto your system.
The Homebrew formulas' are what's used to produce those binaries, or - if there's no pre-compiled one available - that's when it's compiled live on your system.
Seems like a decent tradeoff, as otherwise installing (say) Qt could take an hour+, since that's a bit of a monster to compile. :)
The problem is that every time you install something it will update a gazillion dependencies because there is a minor version difference in a library I don't even use. And of course I did not ask for those binaries to be upgraded.
When I do a yum install, 99% of the cases it just add the package I need. And won't mess with my dev tools.
The Homebrew formulas' are what's used to produce those binaries, or - if there's no pre-compiled one available - that's when it's compiled live on your system.
Seems like a decent tradeoff, as otherwise installing (say) Qt could take an hour+, since that's a bit of a monster to compile. :)