show_batch bombs with a AttributeError: 'tuple' object has no attribute 'show'.
Do I need to wrap that how tuple in a custom class (that derives from Tuple)? Or is there a way to setup the typedispatched show_batch such as: x:(BaseInput,BaseInput) so that it would know to call it?
Yes you do. Python sucks and does not let us check types inside a tuple/collection (e.g. Tuple[Thing, OtherThing] is not something you can use as a type in python, it’s just an artifice in the type annotation system).
I see that show_batch accepts a kwargs argument … how can I pass custom values into it? Is there a way to pass something via a transform or when I create the DataLoaders object vis dblock.dataloaders(...)?
You then have to make sure your images are still encoded as the above tuple type, and do not lose it through your pipeline. Sorry I am still trying to figure out what I did myself.
Mine ended up working eventually, you can look through it here to see if anything helps. This is probably some of the worse code I have ever written, so only skim it. There may even been dead lines that are not used anymore. I was doing this when I had no idea how to use fastai2, and spent a few months working on the project before getting everything to work.