Qt 4.6x Known Issues

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Known issues Qt 4.6.0 & 4.6.1

Ported from Gitorious


Also see common questions in Symbian_FAQ .


  • Qt libraries cannot be compiled with GCCE.
  • Header inclusion like #include <QtTest> won't work for RVCT. Use #include <QtTest/QtTest> instead.
  • The wrapper makefiles created by qmake require GNU make to execute, the make.exe in the Symbian SDKs is sufficient for this. If you have an incompatible make.exe in your path (e.g. the one installed by ARM RVCT), the wrapper makefiles may fail.
  • The wrapper makefiles created by qmake may cause conflicts with raptor's make engine, the workaround is to run sbs directly or to use a GNU make with a different exe name (e.g. mingw32-make.exe) to run the wrapper makefiles.

Symbian emulator

  • Running multiple Qt applications in emulator is not possible. Starting second application will return KErrNotSupported(–5).
  • The Emulator (32-bit Windows application) is limited to 2GB address space. Mwccsym2 links the debug symbols into the executable creating big chunks of memory, this causes a situation where even a small chunk of linear memory is too much to fit into the memory causing application/emulator just bails out without any error note. Error is easy to spot if the executable dies before reaching main() and you have just increased epocheapsize maximum in .pro file.
  • Changing MegabytesofFreeMemory crashes S60 3rd edition FP 1 – emulator at start up.

Installation on the phone

  • Installing the qt.sis, that is shipped with the package, may fail due to stale state on the phone. Please uninstall any technology preview version from the phone, and repeat the installation once more.
  • If Qt libraries are installed to memory card, startup of Qt applications is very slow due to Symbian doing additional checking of libraries found from removable media. Therefore, Qt libraries can only be installed to the phone memory (C:).

General issues (QtCore and QtGui)

  • Sometimes widgets can grow out of the screen boundaries even with widget.showFullScreen()
  • Apps that cause heavy CPU load for long periods can crash the launching process (e.g. application menu) with ViewSrv 11 panic.
  • QLocale Symbian system locale support and QDesktopServices do not work properly in S60 3rd edition FP 1 builds/devices.
  • QFileSystemModel sometimes creates duplicate nodes for files and directories if the file name and path case doesn't match exactly the case of the file name in the file system.
  • Font rendering: Vertical and very big fonts do not yet get rendered optimally.
  • The "About Qt" dialog is too big and impossible to scroll, therefore not fitting properly fit properly on S60 device screen.
  • IAP query dialog can be displayed each time socket tries to connect. For workaround please look at source code for FTP or Anomaly examples. There you can see how to set default IAP.
  • Mouse events are not always sent to the correct receiver when pressing down and dragging.
  • Using virtual keyboard to edit QLineEdit that has input mask only works properly if masked characters are filled in order starting from the beginning of the string.
  • Using QWidget::lower() on a top level window will put the whole application to background. This will most likely be solved in Qt 4.6.1 by introducing separate window groups for each top level window. Note that this solution may impact the contents of the task switcher, making each top level window show up as a separate task.
  • Switching orientation on a S60 3.x (like the N95) takes several seconds for some Qt demos. See bug report here

QtNetwork specific issues

  • Requires networkservices capability to connect to internet. Remember to add target.capability = networkservices in .pro file.
  • Network using examples might crash (ViewSrv 11) when selecting IAP and while waiting for some longer time in "pre-shared key for WLAN" dialog.
  • Network using examples will use first active IAP and that might cause connectivity issues in some cases (i.e. MMS access point in use at that time).

QtWebkit specific issues

  • Requires networkservices capability to connect to internet. Remember to add target.capability = networkservices in .pro file.
  • Add target.epocheapsize 0x200000 0x2000000 in .pro files. This will set your minimum application heap size to 2MB and the maximum to 32MB.
  • Running webkit examples will in most cases require you to increase memory usage of the emulator which can be done by editing MegabytesOfFreeMemory setting in %EPOCROOT%32\data\epoc.ini.
  • Building webkit with -fpu vfpuv2 causes random crashes (kern-exec 3) when running JavaScript code.
  • webcore.pro must be built from command line, building from Carbide runs out of memory.
  • QtWebkit can only be build for release mode in armv5. Building debug will cause the RVCT linker to run out of memory.

Phonon specific issues

  • Video does not playback on S60 3rd edition FP 2 devices. (Fixed in 4.6.1, QTBUG-5467)

Bug Tracker

  • A list of bugs reported on 4.6.0, which are fixed in 4.6.1 or later (or not fixed yet) can be seen at The Bug Tracker
  • This is a public bug tracker, so you can report any newly discovered bugs using the "create new issue" link (after registering)