UbuntuShape crash with latest UITK on mako/flo

[Jean-Baptiste Lallement]

mako rc-proposed/ubuntu 256 + distupgrade of all the packages in the ovrerlay PPA

The shell doesn't come up and unity8 crashes in a loop.

Logs attached.

[Gerry Boland (gerboland)]

Also experiencing it with Flo

[Launchpad Janitor (janitor)]

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

[Gerry Boland (gerboland)]

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.

[Gerry Boland (gerboland)]

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

[Gerry Boland (gerboland)]

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.

[Michał Sawicz (saviq)]

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

[Gerry Boland (gerboland)]

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

[kevin gunn (kgunn72)]

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

[Loïc Molinari (loic.molinari)]

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...