the header xcb/xinput.h is missing

[Impact]
Allow Qt 5.12 to be compiled with full input support. This allows applications to be built using complex input devices such as drawing pads. This is used in e.g Krita which KDE builds into a Snap package for distribution. Currently Krita does not work with pen input devices with pressure sensitivity.

[Test Case]
Install Krita with Qt 5.12 from current Snap and note how pressure sensitivity does not work.

[Regression Potential]
None that I can see, it's just packaging a few new header files.

----

I suspect this means there should be another package, libxcb-xinput-dev perhaps?

I already did sudo apt install "libxcb*dev" to get all related dev packages, but none of them provide xcb/xinput.h.

The result is that when building Qt from source, it's necessary to use a copy of this file which Qt provides (qtbase/src/3rdparty/xcb/include/xcb/xinput.h), because it's missing from the system. So if you don't give the option -qt-xcb to configure, then Qt will be built without multi-touch support.

https://bugreports.qt.io/browse/QTBUG-69045

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: libxcb1-dev 1.13-1
ProcVersionSignature: Ubuntu 4.15.0-23.25-generic 4.15.18
Uname: Linux 4.15.0-23-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Thu Jun 21 08:32:12 2018
DistUpgraded: Fresh install
DistroCodename: bionic
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation UHD Graphics 620 [8086:5917] (rev 07) (prog-if 00 [VGA controller])
   Subsystem: Lenovo UHD Graphics 620 [17aa:3802]
Lsusb:
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 004: ID 0cf3:e300 Atheros Communications, Inc.
 Bus 001 Device 003: ID 06cb:0081 Synaptics, Inc.
 Bus 001 Device 002: ID 04f2:b5da Chicony Electronics Co., Ltd
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: LENOVO 80Y7
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.15.0-23-generic root=ZFS=rpool/ROOT/ubuntu ro
SourcePackage: libxcb
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 02/22/2018
dmi.bios.vendor: LENOVO
dmi.bios.version: 5NCN38WW
dmi.board.asset.tag: NO Asset Tag
dmi.board.name: LNVNB161216
dmi.board.vendor: LENOVO
dmi.board.version: SDK0J40709 WIN
dmi.chassis.asset.tag: NO Asset Tag
dmi.chassis.type: 31
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Lenovo YOGA 920-13IKB
dmi.modalias: dmi:bvnLENOVO:bvr5NCN38WW:bd02/22/2018:svnLENOVO:pn80Y7:pvrLenovoYOGA920-13IKB:rvnLENOVO:rnLNVNB161216:rvrSDK0J40709WIN:cvnLENOVO:ct31:cvrLenovoYOGA920-13IKB:
dmi.product.family: YOGA 920-13IKB
dmi.product.name: 80Y7
dmi.product.version: Lenovo YOGA 920-13IKB
dmi.sys.vendor: LENOVO
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.91-2
version.libgl1-mesa-dri: libgl1-mesa-dri 18.0.0~rc5-1ubuntu1
version.libgl1-mesa-glx: libgl1-mesa-glx 18.0.0~rc5-1ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.19.6-1ubuntu4
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.5-1ubuntu1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:18.0.1-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20171229-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.15-2