`q-rng` data.frame printing error

While stepping through the predict layer for `quantile_reg`, I kept getting errors trying to print a `data.frame` containing `q-rng` distributions. The error is `Error in round(rng[1], digits) : invalid second argument of length 0`. It prints fine as a `vctrs_vctr` when I select the corresponding column, though the output isn't very informative (a vector consisting of `[0.01, 0.99]`).

Sorry if this is a more obscure description than usual, as its hard to actually see the contents to reproduce.