OT: It's never done *this* before

[Mark Geisert]

Hi pbl,

On 5/19/2025 5:31 AM, Philippe Baril Lecavalier via Cygwin-apps wrote:
> On 2025-05-12 5:54 p.m., Mark Geisert via Cygwin-apps wrote:
>> In the midst of yet another long, tedious Qt5-Base build, this happened:
>>
>> And so on for another 136,454 error messages. Somehow g++ has ingested 
>> an executable file via #include; the leading "MZ" is evidence.
> 
> Trying to update qt5 to 5.15?

Yes.  Qt (the company) has declared Qt 5 end of Standard support for May 
26, 2025, i.e. this coming weekend.  I wanted to see if I could get the 
last supported release 5.15.16 available on Cygwin.

> Please and thank you! A bit problematic that the current one is a build 
> from about 2017. I have a doubt on how reliable it can be at this point 
> with potential C++ ABI changes under the hood. I gave that a look not 
> long ago.

Indeed.

> First you have a long list of cygwin-specific patches that are there 
> presumably to have the thing just build. Some might need to be dropped, 
> and some new ones might need to be added (good luck with that part). I 
> know a thing or two about Qt itself but nothing about its bespoke build 
> system.

I am building on Achim's very helpful work-in-progress that moved the 
bar from Cygwin-current Qt 5.9.4 to 5.15.2.  I still need to review 
external patches developed since then and take care of a couple of CVE 
issues.

> Then I tried to just rebuild 5.9. I was greeted early on by a header 
> problem, not too exotic to fix it, and then it was a bunch of errors 
> where it couldn't find a long list of libraries, even though they really 
> are there (jpeg, png, sqlite, etc.). At that point I said "ok another 
> time".

Sounds familiar :-(.  I did manage to install everything needed to 
complete the build but I think I need to re-do that with an eye towards 
minimizing the BUILD_REQUIRES list in the cygport file.

If you happened to have successfully patch the very noisily repeated 
warning about qHash() prototype I'd be keen to include it.  That seems 
to be triggered by almost every source file compilation in the build.
Thanks,

..mark