To take an example of another pytorch library, I’ll use pretrained-models.pytorch (https://github.com/Cadene/pretrained-models.pytorch).You should be able to do:
data = ...create your databunch...
# create model according to pretrained-models docs
model_name = 'nasnetalarge' # could be fbresnet152 or inceptionresnetv2
model = pretrainedmodels.__dict__[model_name](num_classes=1000, pretrained='imagenet')
learn = Learner(data, model)
... do training
That should work in any case where model is a pytorch model. If it doesn’t you should report it here.