WIP: Update Qt to 5.15.2

[mleotta]

This branch pushes Qt5 to the latest 5.15.2. This branch is for CI testing. It may be better to use 5.15 and just skip 5.12.

[dstoup]

Hmmm, made a comment on this yesterday, not sure why it's not here. Below is what I said:

---

Looks like we're bumping into the next issue I've had when poking at Qt upgrades. I think this version is across the threshold of what will work out of the box for Vivia.

IIRC ... the error at the bottom of this message is keeping the current VTK version from configuring correctly on two of the Linux builds . The options I think I had come up with at the time were

1 - Upgrade VTK which Vivia can't use (and actually I don't even know if that helps directly)
2 - There is a VTK_LEGACY_REMOVE flag in VTK that removes the dependence on these features but, Vivia depends pretty heavily on them

It feels like we're quickly approaching a point where Vivia needs some major effort if it's going to be able to keep up with the package version it depends on. I guess one option is just to keep the versions Vivia needs around as non-default and let everything else move forward. If that's the choice here then I think we just need to configure the VTK_LEGACY_REMOVE = ON and things will work but can't remember 100% but willing to test it.

The other build issue I see here is with CentOS 7, gcc 4.8.5. It's possible that a few patches will fix those and it's also possible that some of them already exist in spirit for the older versions but I would have to look more closely. But, this is the second time in two days that I've brought up the issue of minimum supported compiler versions. It's probably getting a bit overdue for making some tough choices about how to proceed. Until then, I can poke at the patches needed to get this PR working.

Lastly, I have no idea what is wrong on the MAC build.

-- Check size of CMake Error at /mnt/ssd/data/Dashboards/jenkins/workspace/FletchLinuxGPUPR/build/install/lib/cmake/Qt5/Qt5Config.cmake:28 (find_package):
Could not find a package configuration file provided by "Qt5X11Extras" with
any of the following names:

Qt5X11ExtrasConfig.cmake
qt5x11extras-config.cmake

[mwoehlke-kitware]

I'm not actually sure how functional Qt on X11 is without Qt X11Extras. I also don't understand why this isn't building; it can certainly exist:

$ rpm -qf /usr/lib64/cmake/Qt5X11Extras/Qt5X11ExtrasConfig.cmake
qt5-qtx11extras-devel-5.15.2-2.fc33.x86_64

FWIW, I have no issues with ViViA + VTK 8.0.1 + Qt 5.15.2. This combination is not unattainable.

I would start by making sure libxkbcommon-dev[el] is installed on the CI machines. It doesn't seem that it is, at least on isla-nublar and urras.

[mwoehlke-kitware]

libinput might also be an issue. Note that the RH7 spec requires:

BuildRequires: pkgconfig(libinput)
BuildRequires: pkgconfig(xcb-xkb) >= 1.10
BuildRequires: pkgconfig(xkbcommon) >= 0.4.1
BuildRequires: pkgconfig(xkbcommon-x11) >= 0.4.1