Why does a statically built Qt use the dynamic Visual Studio runtime libraries ? Do I need to deploy

http://qt-project.org/faq/answer/why_does_a_statically_built_qt_use_the_dynamic_visual_studio_runtime_librar

 

Qt is built using the -MD(d) switch, which links against the dynamic C/C++ runtime libraries. This is necessary as we have experienced memory problems when using anything but the -MD(d) flag, and in general, it is recommended to use. You should not alter this flag yourself for your application, because it conflicts with how the Qt library is built if you change the flag to -MT. You should not change it for Qt either, since it is likely to cause problems.

Qt is still built statically when using the -static option though, meaning you do not need to distribute the Qt dlls when deploying your application. You will have to distribute the C runtimes though (if they don’t already exist on the target machine), see our deployment documentation [qt.nokia.com].

If you choose to change this setting anyway, then it can be done in the qmake.conf file for your qmakespec. Where it says -MD you need to change it to be -MT. For Visual Studio 2005 it is also necessary to change the relevant files in mkspecs/features to remove the call to mt.exe. As stated above, we can’t support you with any problems you run into as a consequence of making these changes.