Cannot compile pgadmin4 mainline

(pgadmin4)markm {~/download/pgadmin4/runtime} kobaz$ git pull
Already up-to-date.
(pgadmin4)markm {~/download/pgadmin4/runtime} kobaz$ git log | head -n 1
commit 4a280b251755091af9bf56bcdee964601df104ae

(pgadmin4)markm {~/download/pgadmin4/runtime} kobaz$ qmake
Project MESSAGE: Building for QT5+...
Project MESSAGE: Using QWebKit...
Project MESSAGE:
Project MESSAGE: ************************************** WARNING
**************************************
Project MESSAGE: * It is strongly advised that Qt 5.5.0 or later is used
to build the pgAdmin runtime.
Project MESSAGE:
*************************************************************************************
Project MESSAGE:
Project MESSAGE: Building for Linux/Mac...
Project MESSAGE: Using /usr/bin/python-config
Project MESSAGE: Python3 detected.

(pgadmin4)markm {~/download/pgadmin4/runtime} kobaz$ make
g++ -c -m64 -pipe -I/usr/include/python3.4m -I/usr/include/python3.4m
-O2 -Wall -W -D_REENTRANT -fPIE -DQT_NO_DEBUG -DQT_WEBKITWIDGETS_LIB
-DQT_WEBKIT_LIB -DQT_WIDGETS_LIB -DQT_NETWORK_LIB -DQT_GUI_LIB
-DQT_CORE_LIB -I/usr/lib/x86_64-linux-gnu/qt5/mkspecs/linux-g++-64 -I.
-isystem /usr/include/x86_64-linux-gnu/qt5 -isystem
/usr/include/x86_64-linux-gnu/qt5/QtWebKitWidgets -isystem
/usr/include/x86_64-linux-gnu/qt5/QtWebKit -isystem
/usr/include/x86_64-linux-gnu/qt5/QtWidgets -isystem
/usr/include/x86_64-linux-gnu/qt5/QtNetwork -isystem
/usr/include/x86_64-linux-gnu/qt5/QtGui -isystem
/usr/include/x86_64-linux-gnu/qt5/QtCore -I. -I. -o pgAdmin4.o pgAdmin4.cpp
In file included from pgAdmin4.cpp:29:0:
BrowserWindow.h:131:37: error: 'QWebEnginePage' has not been declared
void triggerWebViewWindowEvents(QWebEnginePage::WebAction action);
^
BrowserWindow.h:131:63: error: expected ',' or '...' before 'action'
void triggerWebViewWindowEvents(QWebEnginePage::WebAction action);
^
Makefile:398: recipe for target 'pgAdmin4.o' failed
make: *** [pgAdmin4.o] Error 1