kdevplatform 1.7.1 compilation failure cant find QT include files

[Daniel Magree]

on Ubuntu 15.04, qt5, cmake doesn't find the QT include directory. Manually
adding the directory gets the make file generated:
QT_QT_INCLUDE_DIR = /usr/include/x86_64-linux-gnu/qt5

Compiliation fails with output:
/home/<username>/Downloads/kdevplatform-1.7.1/build/sublime/../../sublime/idealdockwidget.h:26:23:
fatal error: QDockWidget: No such file or directory
 #include <QDockWidget>

Should the include search path be added for each of the subdirectories of
/usr/include/x86_64-linux-gnu/qt5?

Here's the qmake output, if thats useful.
qmake -v output:
QMake version 3.0
Using Qt version 5.4.1 in /usr/lib/x86_64-linux-gnu

D
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.kde.org/pipermail/kdevelop-devel/attachments/20150817/e70cff16/attachment.html>