Re: [gentoo-dev] [RFC] Global USE=gui

[Michał Górny]

On Wed, 1 Jun 2016 13:53:31 -0400
waltdnes@××××××××.org wrote:

> On Wed, Jun 01, 2016 at 05:29:55PM +0300, Mart Raudsepp wrote
>
> > It is meant as a feature based USE flag, as opposed to the "extra dep"
> > based USE flags we've been using for this.
> > There are a lot of those with USE=gtk right now. In many cases it's
> > some little add-on graphical utility for a library, or some graphical
> > configuration GUI in addition to command line, or some bigger cases in
> > more modular packages that provide multiple frontends, and not all of
> > them are graphical, but CLI or TUI (TUI meaning ncurses-based or
> > similar).
> > Also there are various with USE=X where it's also about that, but X
> > isn't the only way to do GUI these days (any gtk3 app that doesn't
> > directly use libX11/libxcb/etc themselves natively supports wayland,
> > for example).
> >
> > Essentially, if it's an optional GUI, it'd be behind a USE=gui, instead
> > of USE=gtk, USE=X, USE=qt4 or USE=qt5, when that optional GUI is
> > available in only one toolkit version. So hence feature based flag, not
> > dependency-based.
>
>   I see this as at least a redundancy, if not a problem.  First, let's
> look at the general case.  An optional "UI" (User Interface) is also
> selected...
> * via the "tools" useflag 78 times in use.local.desc
> * via the "ncurses" useflag 10 times in use.local.desc.
> * for a lot of ebuilds via the "ncurses" useflag in use.desc (So why
>   does "ncurses" show up in use.local.desc ???)
>
>  There is no need for an additional "TUI" (Text User Interface) use flag
> for these cases.  "tools" and/or "ncurses" tells you enough.  Similarly,
> "GUI" is grab-bag of gtk2/gtk3/qt4/qt5/X/Wayland/whatever.  The only
> thing they have in common is a hard-coded dependancy on graphics libs.
> "GUI" is an implicit dependancy of gtk2/gtk3/qt4/qt5/X/Wayland/whatever.
> Using any of them tells you enough.  What do we accomplish by requiring
> one more USE flag?  This will also make dependancy resolution of ebuilds
> more complex, i.e. slower.  Why?

Simple regular users don't want to be concerned with choice of toolkit
for every single package, as long as a GUI is provided. Furthermore,
this matches the recommended USE flag design where the more important
flags are provided as feature flags, while specific dependency choice
flags are minor.

-- 
Best regards,
Michał Górny
<http://dev.gentoo.org/~mgorny/>