A backtrace from dropping-letters:
https://jenkins.qa.ubuntu.com/job/trusty-touch-mako-smoke-daily/118/artifact/clientlogs/dropping_letters_app/
ProblemType: Crash
DistroRelease: Ubuntu 14.04
Package: qmlscene
Uname: Linux 3.4.0-5-mako armv7l
Architecture: armhf
CurrentDesktop: Unity
Date: Wed Mar 5 06:51:35 2014
ExecutablePath: /usr/lib/arm-linux-gnueabihf/qt5/bin/qmlscene
ExecutableTimestamp: 1392736183
ProcCmdline: /usr/lib/arm-linux-gnueabihf/qt5/bin/qmlscene dropping-letters.qml
ProcCwd: /usr/share/click/preinstalled/com.ubuntu.dropping-letters/0.1.2.2.43
RetraceOutdatedPackages: outdated debug symbol package for liblttng-ust0: package version 2.4.0~rc4-1 dbgsym version 2.1.1-2
Signal: 11
StacktraceTop:
IsSymbol (this=<optimized out>) at ../3rdparty/v8/src/objects-inl.h:297
Equals (other=0x3ee08089, this=0x3ee0c2f9) at ../3rdparty/v8/src/objects-inl.h:2235
v8::internal::FullCodeGenerator::EmitLiteralCompareTypeof (this=this@entry=0xbeff47f0, expr=expr@entry=0x1a0d770, sub_expr=<optimized out>, check=...) at ../3rdparty/v8/src/arm/full-codegen-arm.cc:4270
v8::internal::FullCodeGenerator::TryLiteralCompare (this=this@entry=0xbeff47f0, expr=expr@entry=0x1a0d770) at ../3rdparty/v8/src/full-codegen.cc:1411
v8::internal::FullCodeGenerator::VisitCompareOperation (this=0xbeff47f0, expr=0x1a0d770) at ../3rdparty/v8/src/arm/full-codegen-arm.cc:4315
UserGroups: adm autopilot cdrom dialout dip nopasswdlogin plugdev sudo tty video
Marking the bug as Incomplete to indicate it's probably not reproducible anymore. Qt Declarative script engine was rewritten in the Qt 5.2.1 and it's likely the crashes that happened with Qt 5.0.2 do not happen or are different with the new Qt.