FLUX.JL -- MethodError: no method matching loss()

I believe I had a similar issue with Flux v0.13 trying to call

loss(m, x, y) = mean(Flux.crossentropy(m(x), y))
Flux.@epochs 10 Flux.train!(loss, m, batches, opt_state)

Changing loss(m, x, y) to loss(m, (x, y)) did the trick.