I tried git version and this is the relevant build log:

Linking CXX executable konsole
cd /var/tmp/portage/kde-base/konsole-9999/work/konsole-9999_build/src && /usr/bin/cmake -E cmake_link_script CMakeFiles/konsole.dir/link.txt --verbose=1
/usr/bin/x86_64-pc-linux-gnu-g++   -O2 -pipe -mtune=native -march=native -fomit-frame-pointer  -std=c++0x -fno-exceptions -Wall -Wextra -Wcast-align -Wchar-subscripts -Wformat-security -Wno-long-long -Wpointer-arith -Wundef -Wnon-virtual-dtor -Woverloaded-virtual -Werror=return-type  -Wl,--enable-new-dtags  -Wl,-O1 -Wl,--as-needed -Wl,--sort-common CMakeFiles/konsole.dir/konsole_dummy.cpp.o CMakeFiles/konsole.dir/konsole_automoc.cpp.o  -o konsole -rdynamic libkdeinit5_konsole.so libkonsoleprivate.so.3.90.900 /usr/lib64/libKF5Pty.so.5.4.0 /usr/lib64/libKF5Konq.so.5.97.0 /usr/lib64/libKF5KDELibs4Support.so.5.4.0 /usr/lib64/libKF5Crash.so.5.4.0 /usr/lib64/libKF5UnitConversion.so.5.4.0 /usr/lib64/libKF5KIOFileWidgets.so.5.4.0 /usr/lib64/libKF5Solid.so.5.4.0 /usr/lib64/libKF5Parts.so.5.4.0 /usr/lib64/libKF5Notifications.so.5.4.0 /usr/lib64/libKF5Bookmarks.so.5.4.0 /usr/lib64/libKF5XmlGui.so.5.4.0 /usr/lib64/libQt5PrintSupport.so.5.4.0 /usr/lib64/libKF5TextWidgets.so.5.4.0 /usr/lib64/libKF5SonnetUi.so.5.4.0 /usr/lib64/libKF5NotifyConfig.so.5.4.0 /usr/lib64/libKF5KIOWidgets.so.5.4.0 /usr/lib64/libKF5WindowSystem.so.5.4.0 /usr/lib64/libKF5IconThemes.so.5.4.0 /usr/lib64/libKF5ItemViews.so.5.4.0 /usr/lib64/libKF5ConfigWidgets.so.5.4.0 /usr/lib64/libKF5GuiAddons.so.5.4.0 /usr/lib64/libKF5Codecs.so.5.4.0 /usr/lib64/libKF5Auth.so.5.4.0 /usr/lib64/libKF5KIOCore.so.5.4.0 /usr/lib64/libKF5Service.so.5.4.0 /usr/lib64/libKF5I18n.so.5.4.0 /usr/lib64/libKF5JobWidgets.so.5.4.0 /usr/lib64/libKF5CoreAddons.so.5.4.0 /usr/lib64/libQt5Network.so.5.4.0 /usr/lib64/libKF5Completion.so.5.4.0 /usr/lib64/libKF5ConfigGui.so.5.4.0 /usr/lib64/libQt5Xml.so.5.4.0 /usr/lib64/libKF5ConfigCore.so.5.4.0 /usr/lib64/libKF5WidgetsAddons.so.5.4.0 /usr/lib64/libQt5DBus.so.5.4.0 /usr/lib64/libQt5Widgets.so.5.4.0 /usr/lib64/libQt5Gui.so.5.4.0 /usr/lib64/libQt5Core.so.5.4.0 -Wl,-rpath,/var/tmp/portage/kde-base/konsole-9999/work/konsole-9999_build/src: 
/usr/lib64/libKF5KDELibs4Support.so.5.4.0: undefined reference to `qMessageFormatString(QtMsgType, QMessageLogContext const&, QString const&)'
collect2: error: ld returned 1 exit status
src/CMakeFiles/konsole.dir/build.make:110: recipe for target 'src/konsole' failed
make[2]: *** [src/konsole] Error 1
make[2]: Leaving directory '/var/tmp/portage/kde-base/konsole-9999/work/konsole-9999_build'
CMakeFiles/Makefile2:159: recipe for target 'src/CMakeFiles/konsole.dir/all' failed
make[1]: *** [src/CMakeFiles/konsole.dir/all] Error 2
make[1]: Leaving directory '/var/tmp/portage/kde-base/konsole-9999/work/konsole-9999_build'
Makefile:117: recipe for target 'all' failed
make: *** [all] Error 2

Reproducible: Always

Steps to Reproduce:
1. install qt-5.4.0 (currently beta)
2. Try to compile konsole from git
3.