Cannot switch variants on macOS

[mitsuba-renderer]

Cannot switch variants on macOS

[Speierers]

My bad! This is now fixed and I added a test for this: b7b7f1d
Thanks for reporting this!

[abhinavvs]

I have the same issue on Linux (Ubuntu 16.04) as well. I had to restart the Python Kernel and only then was I able to switch variants.

Here is the error message I get when switching from scalar_rgb to gpu_autodiff_rgb (which is almost exactly same as the one shown above):

ImportError                               Traceback (most recent call last)
<ipython-input-46-d33d0fecbe85> in <module>
----> 1 mitsuba.set_variant('gpu_autodiff_rgb')

~/mitsuba2/build/dist/python/mitsuba/__init__.py in set_variant(value)
    160         modules = {
    161             'mitsuba.core': (_import('mitsuba.core_ext'),
--> 162                              _import('mitsuba.core_' + value + '_ext')),
    163             'mitsuba.render': (_import('mitsuba.render_ext'),
    164                                _import('mitsuba.render_' + value + '_ext'))

~/anaconda3/lib/python3.7/importlib/__init__.py in import_module(name, package)
    125                 break
    126             level += 1
--> 127     return _bootstrap._gcd_import(name[level:], package, level)
    128 
    129 
~/anaconda3/lib/python3.7/importlib/_bootstrap.py in _gcd_import(name, package, level)
~/anaconda3/lib/python3.7/importlib/_bootstrap.py in _find_and_load(name, import_)
~/anaconda3/lib/python3.7/importlib/_bootstrap.py in _find_and_load_unlocked(name, import_)
~/anaconda3/lib/python3.7/importlib/_bootstrap.py in _load_unlocked(spec)
~/anaconda3/lib/python3.7/importlib/_bootstrap.py in module_from_spec(spec)
~/anaconda3/lib/python3.7/importlib/_bootstrap_external.py in create_module(self, spec)
~/anaconda3/lib/python3.7/importlib/_bootstrap.py in _call_with_frames_removed(f, *args, **kwds)

ImportError: generic_type: type "Ray3f" is already registered!

[wjakob]

cc @Speierers