How to work around Eclipse Luna/GTK bug 339174 (change to not use oxygen)

The bug is described here: https://bugs.kde.org/show_bug.cgi?id=339174 For me it fails with:

java: /build/buildd/oxygen-gtk3-1.0.2/src/animations/oxygencomboboxdata.cpp:87: void Oxygen::ComboBoxData::setButton(GtkWidget*): Assertion `!_button._widget' failed.

Problem is if I go to GTK+ Apperance in Control Module and change to anything other than oxygen Eclipse will look totally awful.

Regardless what theme I use (tried QtCurve and Raleigh) it has the same look with huge padding around all controls etc.

Is it possible to have a sensible look without oxygen GTK?

I have kubuntu-desktop installed over the stock LTS distro.

 $dpkg -l libgtk* | grep -e '^i' | grep -e 'libgtk-*[0-9]'
    ii  libgtk-3-0                             3.4.2-0ubuntu0.8                          GTK+ graphical user interface library
    ii  libgtk-3-bin                           3.4.2-0ubuntu0.8                          programs for the GTK+ graphical user interface library
    ii  libgtk-3-common                        3.4.2-0ubuntu0.8                          common files for the GTK+ graphical user interface library
    ii  libgtk2.0-0                            2.24.10-0ubuntu6.1                        GTK+ graphical user interface library
    ii  libgtk2.0-bin                          2.24.10-0ubuntu6.1                        programs for the GTK+ graphical user interface library
    ii  libgtk2.0-common                       2.24.10-0ubuntu6.1                        common files for the GTK+ graphical user interface library

I've found two solutions:

• disable GTK3 by exporting SWT_GTK3=0, then change the GTK2 theme to something else than oxygen (e.g QtCurve). Without the second step oxygen-gtk2 will crash eclipse too.
• change GTK3 theme - I was unable to change it with the GUI tools provided with KDE. I had to install kde-gtk-config and remove settings.ini in ~/.config