On Sat, Sep 12, 2015 at 6:00 AM, Duncan <1i5t5.dun...@cox.net> wrote: > > Just bite the bullet and create entire USE flag families such that an > ebuild can choose the flag appropriate to how it actually uses it. AFAIK > this would need EAPI help, for reasons given below, but it should be > doable. > > gui > gui-gtk > gui-gtk-2 > gui-gtk-3 > gui-qt > gui-qt-4 > gui-qt-5
I'm going to have to read the rest of your email about 14 times to fully grok it, but one thing that strikes me about this approach, and perhaps mine as well, is that this assumes that USE=-gui should imply USE="-gtk -qt" or similar. What if qt or gtk is used for more than just the GUI. What if the console version of the program still uses other functions in these toolkits besides window decoration/etc? Granted, I suspect that in such a case turning off any of this stuff is probably not build-time-configurable. If you want the console-only version you'd just pass the appropriate command line option (like deluge's --ui option). However, it is conceivable that you could design a build system so that the GUI requires qt and libfoo, spell check requires qt only, and you could build the program with GUI support, spell check support, or neither. If you built with USE="-gui spellcheck" then you'd want qt enabled but libfoo disabled. That is obviously a highly contrived example and perhaps we don't need to worry about this scenario. However, it does illustrate the general danger of making USE flags a strict hierarchy. A hierarchy like qt/qt4 is probably fairly safe, but when you generalize to gui/qt/qt4 you're making the assumption that qt is only used for guis. But I do like the concept, well, conceptually. -- Rich
