I figured it was some internal storage overflowing, and I don't have an issue with the error type. The bit that is confusing is the error *message* - what int doesn't fit into a C long? (especially in the second case of float input where no user level int is involved at all).

It's mostly a theoretical problem though - as far as I am aware, the user that hit it was deliberately testing how far the limits of the "infinite precision" integers promised in the documentation actually extend.