[Development] Proposing CMake as build tool for Qt 6

[Matthew Woehlke]

On 14/06/2019 14.35, Lisandro Damián Nicanor Pérez Meyer wrote:
> On Thu, 13 Jun 2019 at 17:02, Thiago Macieira wrote:
>> That means you should NOT do that strong dependency. app5 should 
>> require qdbus >= Qt5, which means Qt 6's should suffice.>
> Except you can't ship both version in the same binary-package,

...so? Pick one (and only one) to install.

> so there is no way to express that relationship *with versioning*.

Requires: qdbus >= 5.0  # satisfied by qdbus-6.3

The whole point, as I understood it, was that the above is supposed to
work. (If packagers aren't packaging qdbus separately, well, that's
*their* problem.)

On 14/06/2019 15.05, Thiago Macieira wrote:
> I was thinking that you'd split the package so that Qt 3, 4 and 5's 
> qdbus is never installed, but instead you always get the one from Qt
> 6. That means Qt 6 is always installed in a system that needs qdbus,
> regardless of whether any applications use it.
That shouldn't be necessary. Just make "qdbus" a virtual package, and
install the one for which you are willing to drag in Qt.

i.e. qdbus5-5.13 → Provides: qdbus = 5.13

(At this point, I'm talking about things *packagers* need to do. Qt can
just ship /usr/bin/qdbus.)

I'm not sure if package managers are smart enough to pick whichever
concrete package satisfies a virtual dependency with the fewest
dependencies of its own, but again, that's not *Qt's* problem.

-- 
Matthew