Program fails in both rstan and CmdStanR

Modeling
1

I’m facing trouble running the following syntactically correct program in Stan via R, trying both rstan (v. 2.21.2) and CmdStanR (v. 0.1.2).

data {
  int<lower=1> N; 
  vector<lower = 0, upper = 1>[N] intra;
  vector<lower = 0, upper = 1>[N] inter;
}
transformed parameters {
  real<lower = 0, upper = 1> gap;
  real alpha;
  real beta;
  gap = alpha * min(inter) - beta * max(intra);
}
model {
  target += normal_lpdf(alpha | mean(inter), sd(inter));
  target += normal_lpdf(beta | mean(intra), sd(intra));
}

Any ideas on what the problem could be here? rstan aborts my R session and in CmdStanR, the resulting error messages aren’t very informative, simply stating that the chains have finished unexpectedly.

2

Can you upgrade the cmdstanr version?
Latest Github version is 0.3.0.9000. Upgrade using

remotes::install_github("stan-dev/cmdstanr")

Then if the problem persists, run fit$output(1) when the chains finish.