QtWebKit Link Error

[longinicloud]

I am on Windows 7, VS2010 Ultimate. I can build QT5 from source following the instructions on https://qt-project.org/wiki/Building-Qt-5-from-Git#aea23489ce3aa9b6406ebb28e0cda430. Now I am trying to build QtWebKit following the instructions on http://trac.webkit.org/wiki/BuildingQtOnWindows. But I get a lot of link errors against WTF funcitons from building JavaScriptCore.lib. An error example is listed below.

JavaScriptCore.lib(JSGlobalObjectFunctions.obj) : error LNK2019: unresolved external symbol _u_charType_51 referenced in function "bool __cdecl WTF::Unicode::isSeparatorSpace(int)" ?isSeparatorSpace@Unicode@WTF@@YA_NH@Z)

Tried very hard on google and searching this forum, but no lucky. May anyone help me out? thanks in advance.