[Development] Focusing bug fixes to 5.9 branch and patch releases during H1/17

[Thiago Macieira]

On sábado, 11 de fevereiro de 2017 07:08:18 PST charleyb123 . wrote:
> That tool chain was actually at very high quality since its launch a
> year ago (this is their new release model), and I'm aware of companies
> that have relied on that version for commercial development since its
> preview access.

It was, except for the part where they used their new optimiser (the same as 
MSVC 2015 Update 3) that generated broken code...

> IMHO, not providing binaries for that platform is a hindrance to Qt
> adoption.  Intel provides chips to OEMs before launch, and companies
> regularly provide pre-release technology access to allow OEMs time to
> integrate with their products, and I'm suggesting Qt should similarly
> support this type of early-access (we can call it "pre-release" access
> if we want).

We can't provide binaries because, with Visual Studio, the different releases 
are not binary-compatible with each other. If we built our releases with the 
RC, it may not run with your application that you compiled with the final. And 
since we promise to keep our compatibility forwards and backwards inside a 
minor series, we don't like to update the MSVC version so you can just drop in 
the new release and not have to rebuild everything.

Maybe we ought to revisit that.

The next problem is the load on the build servers and on the people doing the 
testing that the generated binaries actually work. See the discussion we had a 
couple of months ago on what we'd release for 5.8 and 5.9. We need to keep the 
number of binaries to a constant number. So adding MSVC 2017 would mean 
dropping something.

But we did make MSVC 2017 work with 5.8. We solved all build issues we could 
find.

> Under this proposal, Qt binaries would be available for MSVC++2018
> when it is previewed, or at least most certainly when it goes to RC.
> Waiting for it to deploy is *way* too late, as the new Microsoft
> release model suggests that developers have been integrating the
> compiler into their tooling for a year before Qt "shows up".

That's unlikely to happen.

How about asking Microsoft to follow up on their promise of keeping binary 
compatibility instead? That way, the binaries built with MSVC 2017 will work 
with 2018 and we don't have to rebuild.

-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center