qtchooser configs

[mgorny]

Based on files used by Arch. Untested on revdeps. Still needs update to Qt eclasses to set QT_SELECT, and maybe an eselect module to control the default.conf (currently not installed).

[mgorny]

A small update: added QT_SELECT to qt4-r2 so that it always uses Qt4. Tested with x11-misc/synergy.

[Pesa]

The approach I had in mind was that qt4-r2 and qmake-utils eclasses used the full path to the actual qmake binary in /usr/lib/qt[45]/bin (falling back to /usr/bin/qmake if it doesn't exist, i.e. on Qt < 4.8.6)

[mgorny]

Will this handle the other Qt binaries? I'm no expert on this, so I assumed there could be some plain calls to other binaries without reusing the path from qmake call.

[Pesa]

Everything else should depend on qmake and how qtcore was built (see e.g. qmake -query output). That being said, we know there are broken build systems out there, especially those based on autoconf, but they need to be fixed regardless. Besides, if a packages supports both qt4 and qt5 (e.g. media-libs/phonon), exporting QT_SELECT won't work anyway.

[mgorny]

And the qt4-r2 eclass won't be of any help, would it? Anyway, how do the first two patches look then?

[Pesa]

Exactly, autoconf-based (or other broken) build systems don't use qt4-r2, so the export won't help, they need to be fixed regardless.

[mgorny]

Any news on this one? I think I implemented everything you requested.

[Pesa]

Sorry I didn't notice you pushed new commits, I have some major issues with github notifications lately... I'll try to review and merge tomorrow at the latest.

[mgorny]

Hmm, I don't get notifications for your comments either.

And no, we don't have a way to get that. But I don't think that having common does matter here. As your research shows, upstreams can't rely on any consistent naming and we should worry only about having a simple way of selecting the correct version via ebuilds.

I also see that my interpretation of qtchooser/*.conf disagrees with Fedora. I'll look into the sources.

[mgorny]

Ok, I see that Fedora is wrong and the second line is supposed to be 'library path' rather than 'prefix'. So my patch is fine :).

[mgorny]

Ping!

[Pesa]

pong! sorry...real life...

[Pesa]

Merged with some fixups, thanks a lot!