On Sun, Aug 2, 2015 at 9:03 PM, Patrick Lauer <[email protected]> wrote: > I find setting USE="qt4 -qt5" a lot more obvious than having USE="qt" (why not > USE="X" ?) which then does different things based on another useflag, > sometimes. Maybe. It's horribly inconsistent and even might change result over > time, which is not very user-friendly.
The problem is that this approach breaks down with scenarios which are likely to be commonplace. I want to use fooplayer and bargrapher which are two qt-based applications. fooplayer only supports qt4, and bargrapher only supports qt5. What USE flags should I set, without restorting to per-package flags? Then I also install klunkybrowser which supports both qt4 and qt5 but not at the same time, so how should I manage my flags for that? The current qt policy just has each package support only one version using USE=qt and while it denies user choice for klunkybrowser it is at least simple. The alternative of "qt means I don't care what version" is also simple - the klunkybrowser maintainer would pick the best default and those who care can override it. The approach qt4=qt4 and qt5=qt5 seems simpler on the surface, but it means that users end up having to set tons of per-package configurations when they don't actually care which one they use, and it also doesn't necessarily hint to users which will give them the best experience on each package. Right now you can get away with just USE="qt4 -qt5" because we don't have many qt5-only packages in the tree (I actually have one I've been holding off on introducing due to qt5 not being in the tree until recently). When that changes the mutually-exclusive flags approach will be very painful. -- Rich
