python-thumbor-wikimedia >= 1.0.5 depends on the VIPS 8 Python bindings, which are currently only available on Stretch. They are completely different than the VIPS 7 bindings.
This is a worthwhile backport for current production image scalers as well, although we should be careful with potentially changed command line argument format between VIPS 7 and VIPS 8.
So far all the backports needed are:
- ilmbase
- openexr
- giflib
- vips