[Interest] QT 6.2/6.3 on AlmaLinux

[Thiago Macieira]

On Sunday, 5 June 2022 17:54:15 PDT Thiago Macieira wrote:
> On Sunday, 5 June 2022 17:48:05 PDT Chris Benesch wrote:
> > After struggling for almost 2 weeks I finally got QT 6.2.4 to work on
> > AlmaLinux 8.
> 
> Is this using the broken Red Hat 8's 4.18 kernel?
> 
> If so, downgrade it back to a couple of months ago or upgrade it again to
> release 392. Red Hat botched the backport of the pidfd feature, which is
> what broke QProcess.
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=2044587
> https://bugreports.qt.io/browse/QTBUG-100174

If changing the kernel is not an option, you can just denature the pidfd 
detection code in qtbase so it fails to detect its (broken) availability. In 
https://code.woboq.org/qt6/qtbase/src/3rdparty/forkfd/
forkfd_linux.c.html#_ZL26detect_clone_pidfd_supportv, change the return to -1.

Unfortunately, I have no good way to properly detect the brokenness of the 
kernel at runtime. Please see the QTBUG for more information, where I think I 
explored the possibilities. There's one that would work, but I preferred not 
to apply it because Red Hat was aware of the problem and was working on a 
solution, so it was meant to be temporary...

... except it took them far longer to actually fix the issue than we had 
anticipated. It wasn't a matter of backporting the patches that they hadn't 
previously backported.

-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Cloud Software Architect - Intel DCAI Cloud Engineering