UbuntuShape crash with latest UITK on mako/flo

Also experiencing it with Flo

Status changed to 'Confirmed' because the bug affects multiple users.

Something suspicious to me, the GL context Mir is giving to Qt is missing the alpha channel:

Settings "QSG_INFO=1", you get:

qt.scenegraph.info: texture atlas dimensions: 2048x2048
qt.scenegraph.info: R/G/B/A Buffers: 8 8 8 0
qt.scenegraph.info: Depth Buffer: 24
qt.scenegraph.info: Stencil Buffer: 8
qt.scenegraph.info: Samples: -1
qt.scenegraph.info: GL_VENDOR: Qualcomm
qt.scenegraph.info: GL_RENDERER: Adreno (TM) 320
qt.scenegraph.info: GL_VERSION: OpenGL ES 3.0 V@53.0 AU@ (CL@)

the A Buffer should be 8.

Just checked with working unity8 (with mir 0.16), Alpha buffer reported missing there too. Must be unrelated issue.

Here's a simple way to reproduce the fail. Stick the following into a file test.qml:

import QtQuick 2.4
import Ubuntu.Components 1.2

Rectangle {
    color: 'green'
    UbuntuShape {}
}

Do "stop unity8" to stop unity8 reboot loop. Then do:

MIR_SERVER_NAME=session-0 MIR_SOCKET=/run/mir_socket QT_QPA_PLATFORM=mirserver qmlscene ~/test.qml

It will hang and eventually crash.

Offending landing:
https://requests.ci-train.ubuntu.com/#/ticket/433

Apitrace of the failing scenario:
http://pastebin.ubuntu.com/12638037/
Driver appears to be crashing while compiling the UbuntShape shader

current action ongoing is to revert the recent uitk landing, then this bug can be closed or priority reduced

So the Adreno 320's driver is crashing there:

lowp float mask = smoothstep(distanceMin, distanceMax, shapeData[yCoord <= 0.0 ? 0 : 1]);

because of the index being computed on the same line, storing it in a variable before fixes it...