fails with: Qwt5/Qwt.so: undefined symbol: _ZTI8QwtWheel

Traceback (most recent call last):
  File "/nix/store/a7vxllq86z9mjkj5ih4n540gdw2f0h9h-brickv-2.1.2/share/.main.py-wrapped", line 57, in <module>
    from brickv.mainwindow import MainWindow
  File "/nix/store/a7vxllq86z9mjkj5ih4n540gdw2f0h9h-brickv-2.1.2/share/mainwindow.py", line 32, in <module>
    from brickv.plugin_system.plugin_manager import PluginManager
  File "/nix/store/a7vxllq86z9mjkj5ih4n540gdw2f0h9h-brickv-2.1.2/share/plugin_system/plugin_manager.py", line 26, in <module>
    from brickv.plugin_system.plugins import device_classes
  File "/nix/store/a7vxllq86z9mjkj5ih4n540gdw2f0h9h-brickv-2.1.2/share/plugin_system/plugins/__init__.py", line 1, in <module>
    from brickv.plugin_system.plugins.ambient_light import device_class as ambient_light
  File "/nix/store/a7vxllq86z9mjkj5ih4n540gdw2f0h9h-brickv-2.1.2/share/plugin_system/plugins/ambient_light/__init__.py", line 24, in <module>
    from brickv.plugin_system.plugins.ambient_light.ambient_light import AmbientLight
  File "/nix/store/a7vxllq86z9mjkj5ih4n540gdw2f0h9h-brickv-2.1.2/share/plugin_system/plugins/ambient_light/ambient_light.py", line 25, in <module>
    from brickv.plot_widget import PlotWidget
  File "/nix/store/a7vxllq86z9mjkj5ih4n540gdw2f0h9h-brickv-2.1.2/share/plot_widget.py", line 26, in <module>
    import Qwt5 as Qwt
  File "/nix/store/p6chssckl3zji935rhv47aihma43hi1k-python2.7-pyqwt-5.2.0/lib/python2.7/site-packages/Qwt5/__init__.py", line 32, in <module>
    from Qwt import *
ImportError: /nix/store/p6chssckl3zji935rhv47aihma43hi1k-python2.7-pyqwt-5.2.0/lib/python2.7/site-packages/Qwt5/Qwt.so: undefined symbol: _ZTI8QwtWheel