Webkit2 build fails

genisim

Build Qt5.3 from sources, follow all steps from build 5.3 doc.
Qt5.3 build success.

Switch to qtwebkit and trying build webkit2

Tools/Scripts/build-webkit --qt --qmakearg="CONFIG+=webkit2" --no-webkit1

Build fails for JavaScriptCore library link :

g++ -Wl,-Bsymbolic-functions -Wl,-z,relro -Wl,--as-needed -fdebug-types-section -Wl,-O1 -Wl,-rpath,/home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib -o ../../bin/jsc .obj/jsc.o -L/home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib -lJavaScriptCore -lWTF -licui18n -licuuc -licudata -lgio-2.0 -lgobject-2.0 -lglib-2.0 -lQt5Core -lpthread

undefined reference to llint_op_create_activation' /home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_put_scoped_var'
/home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_typeof' /home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_resolve_scoped_var'
/home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_end' /home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_is_boolean'
/home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_get_by_id_getter_chain' /home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_resolve_base_to_scope_with_top_scope_check'
/home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_begin' /home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_put_by_id_transition_normal'
/home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_mod' /home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_lesseq'
/home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_is_undefined' /home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_resolve_scoped_var_on_top_scope'
/home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_nstricteq' /home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_create_this'
/home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_debug' /home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_is_string'
/home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_switch_string' /home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_resolve_with_this'
/home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_new_array' /home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so: undefined reference to llint_op_/home/genisim/Sources/QT5/qt5/qtwebkit/WebKitBuild/Release/lib/libJavaScriptCore.so:
..............................

Files :

Source/JavaScriptCore/llint/LowLevelInterpreter.asm
Source/JavaScriptCore/llint/LowLevelInterpreter32_64.asm
Source/JavaScriptCore/llint/LowLevelInterpreter64.asm

exists

And ruby used to generate :
WebKitBuild/Release/Source/JavaScriptCore/generated/LLIntAssembly.h

Build machine is Ubuntu 14.04 / 64bit

What is wrong ?