Error when using kernel = "poly_kernel"

[ayueme]

Hi there,
I'm trying to set the poly_kernel in survivalsvm, But I always get this error: Error in cbind(K, -delta * K) : dims [product 36] do not match the length of object [137] In addition: Warning message: In -delta * K : longer object length is not a multiple of shorter object length.
And I can't fing any help about the poly_kernel. Here's the code:

library(survival)
library(survivalsvm)
survsvm.reg <- survivalsvm(formula = Surv(diagtime, status) ~ ., data = veteran,
                           type = "regression", gamma.mu = 0.1,
                           opt.meth = "ipop", kernel = "poly_kernel")

Could you please give me any suggestions? Thank you very much.