QT4 apps fail with symbol lookup error

[Jochen Schroeder]

Running 16.10 several Qt4 apps fail for me with symbol lookup errors.

Two examples are:
$ kcachegrind
kcachegrind: symbol lookup error: kcachegrind: undefined symbol: _ZNK12QApplication17isSessionRestoredEv

$ python -m pyqtgraph
Traceback (most recent call last):
  File "/usr/lib/python2.7/runpy.py", line 163, in _run_module_as_main
    mod_name, _Error)
  File "/usr/lib/python2.7/runpy.py", line 111, in _get_module_details
    __import__(mod_name) # Do not catch exceptions initializing package
  File "/usr/lib/python2.7/dist-packages/pyqtgraph/__init__.py", line 13, in <module>
    from .Qt import QtGui
  File "/usr/lib/python2.7/dist-packages/pyqtgraph/Qt.py", line 104, in <module>
    from PyQt4 import QtGui, QtCore, uic
ImportError: /usr/lib/python2.7/dist-packages/PyQt4/QtGui.x86_64-linux-gnu.so: undefined symbol: _ZN15QSessionManager16staticMetaObjectE

I suspect this applies to many more qt4 packages (and I've found several similar bugs, e.g. #1534421).

Some googling seems to indicate that this due to a version mismatch?