mod$variables() fails with includes if the model is not compiled first

[rok-cesnovar]

See comments in the example:

library(cmdstanr)

data_code <- "
data {
  int N;
}
"
data_file <- write_stan_file(code = data_code, basename = "data.stan")

model_code <- "
#include data.stan
parameters {
  vector[N] y;
}
model {
  y ~ std_normal();
}
"
model_file <- write_stan_file(code = model_code)

mod <- cmdstan_model(
  stan_file = model_file,
  include_paths = dirname(data_file),
  compile = FALSE
)
mod$variables() #this fails
mod$compile()
mod$variables() # this works