If no explicit bin-edges are passed to the .bin method scipp tries to determine suitable bin-edges based on the values of the coordinate.

If the coordinate has nan values this fails

import scipp as sc
data = sc.data.table_xyz(10)
data.coords['x'][0] = sc.scalar(float('nan'), unit=data.coords['x'].unit)
data.bin(x=4, y=2)

with error BinEdgeError: Bin edges in dim x must be sorted.

The error here is reasonable, we can't construct a binning without dropping the events associated with the nan coord values, and we don't want to do that automatically.
But the error message is not very clear. If we catch this issue before the faulty bin-edges are passed to _cpp.bin we could provide the user with a better error message like: ValueError: coordinate contains nan, could not determine bin edges automatically.