Qt3DQuickExtras headers are never packaged

[Florian Hars]

All the headers for the libraries in the Qt3DQuick<Something> packages (called libqt53dquick<something>5) are in the qt3d5-dev package, except for those for libqt53dquickextras5, which I have not been able to find.

This makes it for example impossible to compile the code from qt3d5-examples:

main.cpp:51:10: fatal error: Qt3DQuickExtras/qt3dquickwindow.h: No such file or directory
   51 | #include <Qt3DQuickExtras/qt3dquickwindow.h>
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.

The file is missing in xenial, eoan, and focal, and present in qt3d5-dev in bionic and groovy:

https://packages.ubuntu.com/search?searchon=contents&keywords=qt3dquickwindow.h&mode=exactfilename&suite=focal&arch=any

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: libqt53dquickextras5 5.12.8+dfsg-0ubuntu1
ProcVersionSignature: Ubuntu 5.4.0-33.37-lowlatency 5.4.34
Uname: Linux 5.4.0-33-lowlatency x86_64
ApportVersion: 2.20.11-0ubuntu27.2
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Fri Jun 5 15:45:20 2020
InstallationDate: Installed on 2020-05-28 (7 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
SourcePackage: qt3d-opensource-src
UpgradeStatus: No upgrade log present (probably fresh install)

[Dmitry Shachnev (mitya57)]

Yes, as you say it is present in Groovy, however we did not include it before because this module is a technical preview and not declared stable by upstream.

See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=909306 for details.