[Development] Deprecation/removal model going into Qt 6

[Lisandro Damián Nicanor Pérez Meyer]

Hi!

On Sun, 2 Jun 2019 at 11:31, Jean-Michaël Celerier
<jeanmichael.celerier at gmail.com> wrote:
>
> >  If existing package of application cannot be rebuilt from source with updated
> Qt version, it's a sure no-go for distibution. Either Qt update will be blocked, or
> application will be thrown away (or application will be somehow patched by other
> people, without you even knowing about that)
>
> - People nowadays will just use the flatpak / appimage / snap / whatever version which will be much more up-to date than Debian Stable's Qt 5.7 (!) or Ubuntu LTS & CentOS 's Qt 5.9 anyways.

You will be amazed on the amount of people that depend upon a
distibution stability and will certainly *not* use flatpaks.
microelectronic CADs setup is just a tiny example of that, and I think
many other examples are around. Distributions exist and don't
dissapear for a reason, even if a number of people use flatpaks or
whatever.

> - boost has the exact same ABI stability issue (e.g. no ABI / API stability guarantees at all) and yet distros seem to manage all the C++ software which uses it without much problems.

Boost is **exactly** the best example of why Qt should not go the same
route. It's totally problematic to have more than two stacks around,
and we **will** have Qt5 and Qt6 for a long time.